Opinion for the Court filed by Circuit Judge WILKEY.
Opinion concurring in the judgment in part and dissenting in part filed by Circuit Judge WALD.
WILKEY, Circuit Judge:This appeal concerns the constitutional validity of regulations promulgated by the *1520National Park Service to restrict demonstrations and other activities on the sidewalk directly in front of the White House. The district court struck down most of the regulations, and modified the others, in an unpublished opinion of 26 April 1984. On appeal the plaintiff-appellees and intervenors contend that the district court’s findings are not “clearly erroneous,” and that this court should defer to those findings in what is essentially a factual dispute. The government, as defendant-appellant, urges reinstatement of the original regulations. It defends the regulations as reasonable time, place and manner restrictions which further substantial governmental interests, most notably the security of the President and the aesthetics of the White House view. We agree with the latter position and uphold the regulations as originally written.
The restrictions embodied in the regulations are of three types. The first set governs the size, construction, and placement of signs on the White House sidewalk. The primary purpose of the sign restrictions is to prevent signs from being used as weapons, as concealment for explosives, or as a means of breaching the White House fence. In light of recent Supreme Court cases which clarify the role of judicial review in the first amendment context, we conclude that the sign restrictions are reasonable as originally drafted. A second type of regulation restricts, but does not prohibit, demonstrations within the “center zone” of the sidewalk. We conclude that this restriction, too, is constitutional as a reasonable means of regulating the place of demonstrations. The government’s interest in preserving a relatively unobstructed view of the White House for tourists and passersby constitutes a legitimate aesthetic goal which is not outweighed by the insubstantial infringement on the demonstrators’ ability to engage in expressive activities. Moreover, while unrestricted access to the center zone might provide demonstrators with optimal media exposure, appellees have no first amendment right to such exposure. The third type of regulation prohibits the placing of parcels, except momentarily, on the sidewalk. Such activity has no expressive content; at most, it may be said to facilitate expression. It is unclear whether the facilitative activity proscribed here implicates the first amendment. Even if it does, however, the parcels restriction is constitutional as a reasonable restriction on the manner in which speech may be exercised; it is narrowly tailored to prevent the concealment of explosive devices within parcels left unattended on the sidewalk.
I. Background
In late 1982 representatives of the National Park Service, the Park Police, the Secret Service and the Department of Justice met to consider ways of protecting the White House and its occupants from terrorist attack.1 The need for increased presidential security had been tragically illustrated by the events of 8 December 1982, when Norman Mayer, a regular protestor on the White House sidewalk, was killed by police officers after threatening to blow up the Washington Monument.2 While the agencies reviewed existing regulations and drafted new ones,3 terrorist activity continued at an alarming rate both at home4 and abroad.5
*1521The National Park Service published interim regulations on 22 April 1983;6 they were to become effective immediately.7 The regulations required that signs and placards displayed on the White House sidewalk8 be hand-held by individuals.9 In addition, they prohibited the deposit of parcels on the sidewalk for longer than one hour and provided that parcels placed on the sidewalk were subject to inspection by police officers.10
On 27 April officers of the United States Park Police arrested three long-time protestors on the White House sidewalk11 for failing to comply with the interim regulations. Those arrested, along with other regular White House demonstrators, filed suit in U.S. District Court two days later seeking declaratory and injunctive relief on the ground that the regulations infringed their first amendment rights of free expression.12 Following an evidentiary hearing on plaintiffs’ motion for a temporary restraining order, Judge William B. Bryant concluded that the Park Service had failed to show “good cause” for dispensing with the notice and comment requirements of the Administrative Procedure Act13 when it issued the interim regulations.14 He enjoined enforcement of the regulations pending publication of a final rule.15
The Park Service complied immediately. It republished the regulations as a proposed rulemaking on 17 May 1983, with a public comment period extending to 31 May.16 The Service received fifteen comments, seven of which supported the regulations as proposed and eight of which opposed some portion of them.17 The Service studied the comments, modified its interim regulations and published a “final rule” on *152217 June 1983.18 The plaintiffs amended their complaint seven days later to take account of the new provisions.19
The regulations impose three types of restrictions on activities conducted on the White House sidewalk. The first set of provisions governs the construction, size and placement of signs carried by demonstrators and other individuals. Signs must be constructed of cardboard, posterboard or cloth, while sign supports must be made of wood.20 Signs can be no larger than three feet in height,21 twenty feet in length, and one-quarter inch in thickness, while sign supports must have cross-sectional dimensions of no greater than three-quarters of an inch.22 All signs on the sidewalk must be “attended,” a requirement which is met only if the sign is in physical contact with a person.23 Stationary signs may be no closer than three feet to the White House fence,24 and no sign may be leaned against or attached to the fence or other structure on the sidewalk.25
A second type of restriction concerns the “center zone,” an area defined as the central twenty yards of the sidewalk.26 Within the center zone, signs may not be held, placed or set down, but “individuals may demonstrate while carrying signs ... if they continue to move along the sidewalk.” 27
The third type of restriction prohibits the deposit of parcels and other property on the ground. An exception is made for items which are “momentarily placed or set down in the immediate presence of the owner.”28
The Park Service prefaced its final regulations with a concise explanation of the governmental interests they were designed to serve. Those interests were threefold: “to minimize potential threats to the [White House] and its occupants and visitors ... to provide opportunities to the visitor to view the White House, and to maintain the free flow of pedestrian and emergency traffic.”29 The Service described in detail the manner in which its regulations were designed to accomplish those ends; in doing so, it relied on its own experience as *1523well as that of other federal agencies charged with the protection of the White House and its grounds. The Park Service discussed at length the objections which various commentators had registered to the interim regulations, and it noted modifications which it had made in the regulations to take account of criticisms it found valid.
Following an evidentiary hearing the district court entered a preliminary injunction against enforcement of many of the restrictions on 19 July 1983.30 In the court’s view, “the governmental interests served by the regulations could be attained through alternative means which are less intrusive on first amendment freedoms.”31 The court proceeded to “finetune” the regulations: not only did it uphold some restrictions and reject others, it modified the content of individual provisions by substituting its factual judgment for that of the agency. The court approved the twenty foot limit on the length of signs, but created a special exception for those held parallel to the fence.32 It endorsed the concept of restricting sign and parcel placement, but held that the “physical contact” requirement for signs and the prohibition on parcel placement were unnecessarily restrictive.33 In their place, the court fashioned a rule which allowed signs and parcels to be placed on the sidewalk if they were “attended at all times,” with “attendance” defined to mean “in the immediate presence of the owner.”34 The court approved without modification only three provisions: the restriction on sign materials,35 the center zone restriction,36 and the absolute prohibition on the placement of structures on the sidewalk.37
The government appealed the district court’s order, and its appeal was heard on an expedited basis. In a brief per curiam opinion this court modified the preliminary injunction to take greater account of the government’s interest in presidential security.38 It noted that review of a preliminary injunction ordinarily proceeds under the abuse-of-discretion standard,39 but that an appellate court has greater authority to modify such an injunction where the security of the President is at stake.40 The modifications which this court undertook to make, however, were of the same genre as-those which the district court itself had *1524made earlier.41 An “attended” sign was now defined as one “within three feet of the person responsible for controlling it”;42 no explanation was given for the arbitrary three-foot figure and no attempt was made to define “control.” Signs could be leaned against, or placed within three feet of, the White House fence, but the district court was instructed to set a limit “as to the size, number, and spacing” of such signs.43 Hollow metal tubes were to be permitted as sign supports, but only if their ends were “permanently secured.”44 The parcels restriction was allowed to stand, but plaintiffs were permitted to request an exemption for “a reasonable inventory of pamphlets, leaflets and similar writings.”45
This court’s modifications only applied to the preliminary injunction; they did not preclude de novo consideration of the merits.46 On 23 August the district court modified its order to take account of this court’s decision and set the case for trial on an expedited basis.47
At trial the court heard testimony from more than twenty witnesses. Among those who testified for the government were several Secret Service and Park Police officials with special expertise in the field of White House security.48 Those officials testified at length as to the security rationales underlying each regulation; they emphasized the need to anticipate ingenious and unprecedented forms of terrorism.
On 26 April 1984, the district court issued the decision and order appealed from *1525here.49 It invalidated virtually all of the restrictions on the ground that they did not advance the government’s interest in security. In order to prevail, the court wrote, “the government must show at least a probable danger to the security of the President and the White House created by the plaintiffs’ activities. That is to say, it must establish a nexus between the activity it would proscribe and a threat to presidential security.”50 The court found that the demonstrators’ activities posed no direct threat to the safety of the President.51 Despite the fact that “security measures should be predicated on a ‘better safe than sorry’ premise,”52 the court described the challenged regulations as “totally ineffective” and “demonstrably too restrictive.”53 Its analysis of individual provisions was equally conclusory. The ban on wooden signs was “unjustified,” and any testimony to the contrary was “incredible.”54 The requirement that protestors maintain physical contact with their signs, and the prohibition on stationary signs within three feet of the fence, was “oppressive.”55 The government’s fear that terrorists might conceal explosives or rockets inside hollow metal supports was “grossly exaggerated.” 56 The center zone restriction was “not justified on any score,”57 while a flat ban on the deposit of parcels was “clearly overbroad and unreasonable.”58
Having concluded that the regulations as originally written were in violation of the first amendment,59 the district court proceeded to reject some provisions and to rewrite others. The government had argued that “[United States v. ] O’Brien [391 U.S. 367, 88 S.Ct. 1673, 20 L.Ed.2d 672 (1968) ] does not contemplate ad hoc regulatory supervision by the courts over the details of an administrative scheme, and that in fact, the Supreme Court has warned that ‘[t]he logic of ... elaborate less-restrictive-alternative arguments could raise insuperable barriers to the exercise of virtually all [regulatory] powers’ (United States v. Martinez-Fuerte, 428 U.S. 543, 557, n. 12, 96 S.Ct. 3074, 3082, n. 12, 49 L.Ed.2d 1116 (1976).”60 The district court rejected the applicability of MartinezFuerte. Because that case dealt with the fourth amendment’s protection against un*1526reasonable searches and seizures, the court concluded that it did not state the standard of judicial scrutiny to be applied in first amendment cases. As a matter of “constitutional necessity,” courts should engage in a much more stringent review of governmental action when first amendment interests are at stake.61
The court permanently enjoined the enforcement of every provision as written except for the one-quarter inch limitation on the thickness of signs.62 The requirement that signs be attended and the restriction on the deposit of parcels also survived, but in significantly different form from that which the agency had adopted. Signs were considered “attended” when they were within five feet of the person controlling them.63 Parcels were permitted on the sidewalk when they were within the “immediate presence” of the owner; the same five-foot rule was to be applied in determining “immediate presence.” 64
The government appealed to this court. While the case was pending and before oral argument the Supreme Court decided two cases of major import for the reasonable restriction of free speech within public fora.65 It is primarily our responsibility on this appeal to determine what significance these and other recent Supreme Court decisions have for the regulation of demonstrations on the White House sidewalk.
II. The Legal Standard
Certain types of places are so vital to a healthy and robust public discourse that they are accorded special status under the first amendment. The government cannot constitutionally prohibit all expressive activities in these public fora;66 access to them is a small but invaluable part of every American’s heritage.
The public sidewalk here is one such forum.67 Sidewalks, like streets and parks, are places whose title has “immemorially been held in trust for the use of the public.” 68 As such, they occupy a privileged *1527position in the hierarchy of first amendment jurisprudence.69
The government is not precluded, however, from regulating expressive activities conducted on the White House sidewalk.70 It may adopt reasonable “time, place and manner” restrictions on the exercise of free speech, so long as the restrictions are content-neutral, are narrowly tailored to serve a significant governmental interest, and leave open ample alternative channels of communication.71
The regulations challenged here are clearly not based “upon either the content or subject matter of speech.”72 There is nothing in the text or the history of the regulations to suggest that one group’s viewpoint is to be preferred at the expense of others. They meet the test of being content-neutral. Appellees contend that the Park Service has applied the regulations in a discriminatory fashion, favoring demonstrators who espouse Administration views and disfavoring those with contrary positions, but we find the evidence for such discrimination speculative and unpersuasive. The government has offered cogent explanations for the handful of instances in which the regulations were applied unevenly; we conclude that those aberrations were the product of happenstance and unavoidable circumstances rather than of improper motives. Needless to say, no court will tolerate any attempt to discriminate among protestors on the basis of viewpoint or subject matter.
Nor do we believe that the purpose underlying the regulations was to ban speech entirely. Appellees direct our attention to a memorandum, dated 13 January 1983, from then-Seeretary of the Interior James Watt to an aide, Moody Tidwell. Watt requested “a briefing on the regulations that allow demonstrations and protestors in Lafayette Park and in front of the White House on Pennsylvania Avenue. My intention is to prohibit such activities and require that they take place on the Ellipse.”73 In March 1983 Watt received a briefing from the principal drafter of the new regulations and told him to “keep up the good work.”74
On the circumstances existing during the relevant time here, a strong argument could have been made that a regulation banning all demonstrations on the White House sidewalk and in Lafayette Park would have been unconstitutional.75 But .the institution of a total ban is not the approach the Park Service took; indeed, it is one the Service explicitly rejected. In its preamble to the final regulations, the Service stated that “legal precedent in the District of Columbia Circuit would prevent prohibiting demonstrations altogether on the White House sidewalk.”76 More relevant now may be recent precedent in the Supreme Court,77 but, whether currently accurate as a statement of law or not, this is but one of several indications that the Park Service dealt with constitutional values with scrupulous care.
*1528The regulations also clearly satisfy the constitutional requirement that they leave open ample alternative channels of communication. Demonstrators on the sidewalk are free to engage in a rich variety of expressive activities: they may picket, march, hand out leaflets, carry signs, sing, shout, chant, perform dramatic presentations, solicit signatures for petitions, and appeal to passersby. The content of the message they espouse is theirs and theirs alone; they may express views and employ verbal formulae that would be punished as seditious libel, blasphemy or obscenity in less free societies. Although they may not engage in stationary protest within the center zone of the sidewalk, they are in no way precluded from engaging in other forms of expression there, and they may stand still on the remaining 93% of the sidewalk. Should they find the government’s regulations too restrictive they may always carry their demonstration immediately across Pennsylvania Avenue to Lafayette Park. In short, the regulations leave unaffected a multitude of possibilities for meaningful protest on the sidewalk and within a few yards in adjoining areas.
The regulations also clearly serve a “substantial governmental interest.” No one can deny the substantiality or the significance of America’s interest in presidential security.78 At stake is not merely the safety of one man, but also the ability of the executive branch to function in an orderly fashion and the capacity of the United States to respond to threats and crises affecting the entire free world. Nor is the interest in pedestrian safety and traffic insubstantial; the value of sidewalks as public fora would be considerably vitiated were the state unable to provide for the orderly passage of those persons who use them.79 Finally, the government has a substantial interest in the preservation and enhancement of the human environment; aesthetics are a proper focus of governmental regulation.80
As in most “time, place and manner” cases, the decisive inquiry here is as to the requisite narrowness of the means employed by the government to advance its substantial interests.81 Appellees contend that this is primarily a factual matter, and that an appellate court should refrain from overturning the decision of the trial court unless that decision is “clearly erroneous.” 82 Furthermore, appellees suggest that a trial court has the power to substitute its factual judgment for that of an agency where the agency has chosen not to adopt the “least restrictive” regulatory alternative.
We reject both contentions. The issue for decision on this appeal is not factual, it *1529is legal: did the Park Service draft regulations that were “narrowly tailored to serve a significant governmental interest”? The agency in this case was the institution charged with the principal resolution of factual issues; the court’s role was limited to determining whether the regulations which the agency adopted were within the boundaries of constitutionality prescribed by the first amendment. If they were, it is not the province of the court to “finetune” the regulations so as to institute the single regulatory option the court personally considers most desirable. Courts possess no particular expertise in the drafting of regulatory measures;83 their role is to uphold regulations which are constitutional and to strike down those which are not.
Our analysis is informed by recent Supreme Court interpretations of the “narrowly tailored” requirement. In Clark v. Community for Creative Non-Violence84 the Court upheld a Park Service regulation which prohibited camping in certain parks in Washington, D.C. The Service had used the regulation to deny plaintiffs’ request for permission to sleep in Lafayette Park and the Mall as part of a vigil symbolizing the plight of the homeless in America. This court, sitting en banc, held by a six to five vote that application of the regulations so as to prevent sleeping in the parks would infringe the demonstrators’ first amendment rights.85
The Supreme Court reversed.86 Assuming but not deciding that sleep may be an expressive activity,87 it noted the substantiality of the government’s interest. in “maintaining the parks in the heart of our capital in an attractive and intact condition.” 88 It concluded that the Park Service regulation was a reasonable restriction on the time, place and manner of speech.89 In doing so it criticized the majority of this court for second-guessing the Park Service’s judgment:
We are unmoved by the Court of Appeals’ view that the challenged regulation is unnecessary, and hence invalid, because there are less speech-restrictive alternatives that could have satisfied the government interest in preserving park lands. There is no gain-saying that preventing overnight sleeping will avoid a measure of actual or threatened damage to Lafayette Park and the Mall. The Court of Appeals’ suggestion that the Park Service minimize the possible injury by reducing the size, duration, or frequency of demonstrations would still curtail the total allowable expression in which demonstrators could engage, whether by sleeping or otherwise, and these suggestions represent no more than a disagreement with the Park Service over how much protection the core parks require or how an acceptable level of preservation is to be attained. We do not believe, however, that either United States v. O’Brien or the time, place, and manner decisions assign to the judiciary the authority to replace the Park Service as the manager of the Nation’s parks or *1530endow the judiciary with the competence to judge how much protection of park lands is wise and how that level of conservation is to be attained.90
In Regan v. Time, Inc.91 the Court considered a federal statute which made criminal the publication of photographs of United States currency in color or within a specified size range. The Court upheld the color and size requirements as reasonable restrictions on speech.92 In doing so Justice White and a plurality of the Court again rejected the notion that courts may arbitrarily substitute their judgment for that of legislative or administrative institutions:
Time contends that although the color restriction serves the Government’s interest in preventing counterfeiting, it is nonetheless invalid because it is not narrow enough. Time asserts that the color restriction applies to an illustration of currency regardless of its capacity to deceive and is thus broader than is necessary to achieve the Government’s interest in preventing counterfeiting. However, Time places too narrow a construction on the Government’s interest and too heavy a burden on those enacting time, place, and manner regulations____ It is ... sufficiently evident that the color limitation serves the Government’s interest in a substantial way. That the limitations may apply. to some photographs that are themselves of no use to counterfeiters does not invalidate the legislation. ■ The less-restrictive-alternative analysis invoked by Time has never been a part of the inquiry into the validity of a time, place, and manner regulation. It is enough that the color restriction substantially serves the Government’s legitimate ends.93
Justice Stevens expressed a similar view in his concurrence:
It may well be, as Time argues, that “Congress can do a much better job in preventing counterfeiting than the *1531present § 474 and § 504,” Br. for Appellee 46. The question for us, of course, is not whether Congress could have done a better job, but whether the job it did violates Time’s right to free expression. It does not____94
Clark v. CCNV and Regan v. Time clarify the respective institutional roles of administrators and judges. The expertise of administrators lies in selecting policy goals and in devising techniques with which to pursue them. In the course of performing their twin roles administrators consider evidence which is predominantly factual in nature. Such inquiries, however, seldom lead to a single, determinate result. More often they suggest a number of feasible alternatives, each of which is capable of accomplishing the agency’s goals within acceptable parameters of accuracy and effectiveness. Where a regulation restricts the time, place or manner of speech, however, feasibility is not enough: the regulation must also satisfy the first amendment requirement that it be “narrowly tailored.” The Supreme Court’s test defines a subset of regulatory options which are both feasible and constitutional; it is within this zone of constitutionality that agencies are permitted to exercise discretion in selecting regulatory initiatives.95
The expertise of courts lies in determining whether an agency’s decision is within the zone of constitutionality, not in choosing between options within that zone.96 A court may not require that the agency adopt the “least restrictive alternative,” thereby substituting its judgment for that of the regulators.97 In short, if the regulation lies within the zone prescribed *1532by the first amendment it is constitutional and must be affirmed as such by a court before which it is challenged.
We turn, then, to an examination of the individual regulatory measures adopted by the Park Service, bearing in mind that the expertise of several federal agencies, including that of the Secret Service, contributed to their content.
III. The Regulations
A. Sign Restrictions
The first set of regulatory provisions governs the construction, size and use of signs carried on the White House sidewalk. They prohibit persons from
a. leaning or attaching signs against the fence;
b. demonstrating with signs that are not “attended,” with attendance defined as the maintenance of physical contact;
c. holding stationary signs closer than three feet to the fence;
el. holding signs not made of cardboard, posterboard or cloth;
e. holding signs larger than three feet in height, twenty feet in length, and one-quarter inch in thickness;
f. using sign supports not made of wood with cross-sections larger than three-quarters of an inch by three-quarters of an inch.98
The district court permanently enjoined the enforcement of all but two of the sign provisions. It upheld the one-quarter inch limitation on the thickness of signs;99 it also approved the requirement that signs be “attended,” but redefined “attendance” to mean “within 5 feet of the persons responsible for controlling them.” 100 Appellees defend the trial court’s modification; appellants urge us to reinstate the original language.
While the Park Service advanced other governmental interests as a justification for the sign provisions,101 it is clear that the principal interest they are designed to serve is that of presidential security. This court has described the safety of the Presi*1533dent as a “paramount interest”;102 we have held that the protection of the White House and its occupants justifies “a greater limitation than would be applicable generally to use of public streets and parks.” 103
Just as the White House area is a “unique situs” for first amendment activity,104 it is also a unique situs for considerations of presidential and national security. Despite the significant amount of time modern Presidents spend travelling, they and their families are in residence at the White House far more than they are away. Not only the President, but the Vice-President, the White House Chief of Staff and other high Administration officials have their offices in the Mansion. The White House is the nerve center for America’s national security network, with facilities for coordinating the activities of American diplomats, intelligence agents and military personnel around the globe. Indeed, it is not surprising that the “hot line” and the Situation Room, both located within the Mansion, have become two of the most evocative symbols of national security in an increasingly dangerous age of nuclear tension.
For a structure of such obvious significance to presidential and national security, the White House is singularly exposed to potential terrorist attack. It is located in the middle of a densely populated metropolitan area. A major thoroughfare, Pennsylvania Avenue, runs alongside the White House sidewalk, while busy E Street bounds the Mansion’s lawn to the south. Although airplanes are legally prohibited from flying over the White House, the presence of the National Airport flyway a mile to the west presents a latent security danger. So, too, does the construction of tall office buildings within a few blocks of the Mansion.105
In short, the need for effective security in the vicinity of the White House is great, but the geographical position of the Mansion renders it inherently insecure. Several federal agencies have brought considerable experience and expertise to bear on the problem of White House security; the regulations challenged here are but one fruit of their endeavors.
Considered as part of a larger effort to safeguard the Mansion and its occupants, the sign provisions clearly represent an appropriate means of promoting the substantial governmental interest at stake. They are narrowly tailored to avert specific forms of terrorism.106 Thus, the size limitations are designed to ensure that activities occurring on the sidewalk are not obstructed from police view. The interest at *1534stake is one which cannot be promoted solely through the assignment of additional police officers to the sidewalk: no matter how large the police presence, large signs make observation and communication among officers more difficult. The requirement that signs be constructed of nonrigid materials is designed to prevent them from being used to scale the White House fence, or turned upon police-officers or other demonstrators as weapons. The restriction on the composition of sign supports similarly prevents their use as weapons, either in hand-to-hand struggle or as a means of launching projectiles. The prohibition on the leaning of signs against the White House fence ensures that terrorists will not be able to hide explosives or other deadly objects in the triangular area between the sign and the fence ledge. Finally, the requirement that a demonstrator maintain physical contact with his or her sign is another means of ensuring that signs are not turned into weapons or used to conceal dangerous items.107
The measures adopted by the Park Service are clearly not the only means by which that agency could have sought to deter illegal activity on the sidewalk. There may even be options the Service rejected which would have promoted its interests in a more effective fashion. We are not at liberty, however, to replace the agency’s judgment with our own. It is sufficient that the means selected be “narrowly tailored”: that they lie within the range of feasible options the agency was constitutionally permitted to consider. The sign provisions clearly satisfy this element of the time, place and manner test.
B. Center Zone Restriction
The challenged regulations provide in part that
No signs or placards shall be held, placed or set down on the center portion of the White House sidewalk, comprising ten yards on either side of the center point on the sidewalk; Provided, however, that individuals may demonstrate while carrying signs on that portion of the sidewalk if they continue to move along the sidewalk.108
The asserted governmental interest in imposing additional restrictions for demonstrations within the “center zone” is that of preserving unimpaired the public’s view of the Presidential Mansion from Pennsylvania Avenue and Lafayette Park.109 No considerations of security or safety are at stake; the governmental interest derives wholly from aesthetic concerns.
It is well established that the government’s power to regulate private affairs encompasses the power to promote aesthetic goals.110 While judgments based on aesthetic considerations are inherently *1535more subjective than other types of decisions, they nonetheless reflect values of great significance in everyday life. A decision to ban all billboards from a residential neighborhood may be as important to the people who live there as the assignment of additional police officers to the area; the presentation of an historic building111 may do more to enhance the quality of life in a city than the construction of a new freeway.
Recent decisions of the Supreme Court establish that aesthetic considerations may justify otherwise reasonable time, place and manner restrictions on speech.112 Re-cause the interests at stake are inherently *1536subjective, however, they must be “carefully scrutinized to determine if they are only a public rationalization of an impermissible purpose.” 113
We are convinced that the restriction challenged here does not mask constitutionally improper motives. Three factors are relevant to our analysis.
First, the government has regulated for the benefit of the public rather than for the promotion of its own aesthetic preferences. It is the view of the White House, not from it, which is being preserved. Whatever would be our ruling in the latter case, the purpose of the regulation here is clearly proper.
In order to establish the constitutionality of an aesthetic regulation of speech, the government must show that the regulation was enacted for purposes other than the effectuation of its drafters’ personal tastes. Some resort must be had to societal preferences. To be sure, the preference ultimately embraced need not be that held by a majority of the populace. The government is entitled to rely on the expert judgment of artists, architects, urban planners, design consultants, historians, and other professionals; it is not limited to the prevailing style, but may embrace the innovative and the avantgarde. The aesthetic judgment it makes need not sit well with all citizens, for the debate sparked by an unconventional choice often leads to a richer and more complex appreciation of what is aesthetically pleasing.114 In short, the government need not endorse that which is popular or prevalent, but it must always act on society’s behalf rather than its own.115
Arbitrariness or capriciousness in the selection of aesthetic goals may indicate the presence of an impermissible motive either to enact the preferences of individual government officials or to burden unreasonably the exercise of free speech.116 A requirement that all signs carried on the White House sidewalk be of a certain color, for example, would be suspect because it appears to serve no legitimate social interest in aesthetics. For similar reasons the center zone restriction would be suspect were it shown that the public regards the presence of stationary signs directly in front of the White House as aesthetically pleasing. This in essence is what appellees argue; they contend that for many tourists the “White House experience” includes the presence of stationary demonstrations in *1537the center portion of the sidewalk. This may be true, although why signs in the center zone as well as for more than a hundred yards on either side are essential for some visitors’ “White House experience” has not been explained. As the public comments reveal, however, many other tourists believe that the proliferation of stationary signs within the center zone substantially detracts from their ability to view the White House and its grounds. The Park Service was therefore required to choose between two conflicting views of what is aesthetically pleasing.117 Its decision to preserve twenty yards of the White House sidewalk was not unreasonable; the Service could conclude that most Americans share the latter aesthetic preference, and that stationary protests block more of the White House view than do mobile ones.118 Far from being arbitrary, the Service’s decision represented an exercise of informed discretion based upon what a sizable portion of society regarded as aesthetically significant.
The second factor we must consider in assessing the center zone restriction is the extent to which it burdens speech. The more restrictive an aesthetic regulation, the closer a court must look to determine if it is based on constitutionally improper motives.
The center zone restriction burdens speech only in an indirect and insubstantial way. Protestors are free to engage in a wide variety of expressive activities within the center zone; they are only precluded while there from engaging in stationary protest. The center zone occupies no more than seven percent of the total length of the sidewalk; protestors may remain stationary along any portion of the remainder.
Appellees contend, however, that the regulation makes it more difficult for them to attract media attention to their cause. They assert that the center zone of the sidewalk is a particularly evocative site for symbolic protest, and that stationary demonstrations there are given preferential coverage by the news media. To deny *1538them the opportunity to engage in such protest, they argue, is to deny them effective access to the media.
We find appellees’ contentions unpersuasive for two reasons. First, the government introduced into evidence several photographs which show that the Mansion can clearly be seen from non-central locations on the sidewalk. Second, and more importantly, our caselaw does not recognize a constitutional right to attract media attention to one’s cause. As this court stated in Vietnam Veterans Against the War v. Morton,119 “What the litigant’s press agent seeks and what the public interest requires differ widely. Although every man is entitled to make his remonstrance, no man is entitled to make such a remonstrance that it will be carried on all three television networks.”120
The final consideration relevant to our analysis is that the center zone restriction is not an isolated attempt to regulate the aesthetics of the White House view. If it were we might engage in a more searching inquiry to ensure that the agency has regulated for genuinely aesthetic reasons and not for the purpose of curtailing protected expression. The regulation here, however, is but one element of a continuing effort by the Park Service to preserve and enhance the view of the White House for tourists and passersby. The White House and its grounds are maintained year-round in a scrupulously manicured condition; indeed, only this summer the north facade of the Mansion underwent extensive restoration. The White House lawn is designed and maintained such that tourists on the sidewalk are afforded an excellent view of the Mansion. The fence which separates the sidewalk from the White House grounds is designed to facilitate rather than obstruct that view. It is obvious that the Park Service has promoted, in a number of ways, the ability of Americans to enjoy the beauty of the White House and its grounds. The center zone restriction is only one example of the Service’s commitment to aesthetic values and their effective implementation.121
We find no evidence that the center zone restriction was enacted for any purpose other than the preservation and enhancement of the White House view for tourists and passersby. Because the Park Service based its aesthetic judgment on societal preferences rather than the preferences of individual officials, because the regulation it adopted is not unduly restrictive of free expression, and because the regulation constitutes part of a comprehensive effort to preserve the aesthetics of the White House view, we conclude that the provision is constitutional.
C. The Parcels Restriction
The regulations provide that
*1539No parcel, container, package, bundle or other property shall be placed or stored on the White House sidewalk ... Provided, however, that such property, except structures, may be momentarily placed or set down in the immediate presence of the owner on those sidewalks.122
The district court found this prohibition “clearly overbroad and unreasonable.”123 It rewrote the rule to provide that “parcels or other property be in the immediate presence of the owner, where ‘immediate presence’ shall be defined as within 5 feet of the owner.” 124 Appellees urge this court to affirm the modifications.125 They argue that the original provision makes it more difficult for protestors such as the elderly and handicapped, or mothers with small children, to take part in prolonged demonstrations. These protestors, they contend, must have available to them such items as medical supplies and infant necessities to be able to remain on the sidewalk for any extended period of time. The government, by contrast, seeks reinstatement of the original language.126
We are not entirely convinced that the first amendment protects the conduct proscribed by the parcels restriction.127 That amendment only protects activity which may be fairly characterized as speech. Courts have correctly recognized that some forms of conduct are sufficiently expressive to warrant constitutional protection,128 but by no means all conduct which is intended by the actor to express an idea is speech.129 Intent is but one half the calculus; 130 a court must also consider whether “in the surrounding circumstances the likelihood was great that the message would be understood by those who viewed it.”131 Those types of conduct which the Supreme Court has held are within the ambit of the first amendment — most notably, demonstrating,132 marching,133 picketing,134 wear*1540ing armbands,135 leafletting,136 and affixing a peace symbol to the American flag137 — clearly satisfy both the subjective and objective requirements of the constitutional test.138
By contrast, the activity at issue here— placing parcels on the sidewalk — appears to satisfy neither. Appellees have made no credible claim that such activity is “in-ten[ded] to convey a particularized message”; 139 nor have they shown that onlookers would regard their conduct as communicative.140 Parcels are, of course, inherently less expressive than signs; while the requirement that demonstrators maintain physical contact with their signs directly implicates expressive activity, the parcels restriction does not.141
At most, the activity proscribed by the parcels restriction facilitates expression.142 The first amendment protects facilitative activity only insofar as its restriction imposes burdens on expression itself.143 Neither the Supreme Court nor the lower federal courts, however, have enunciated a test for determining how substantial a burden on expression is necessary before the first amendment is implicated.144 While it is obvious that not just any minimal effect will do, this court is left without *1541guidance for determining whether the alleged burden in this case is sufficient to trigger constitutional protection.
It is unnecessary for us to resolve this potentially thorny issue, however, because the parcels restriction clearly survives scrutiny under the reasonable time, place and manner test. The provision is narrowly tailored to address a security problem of the greatest magnitude, that of parcels left unattended on the White House sidewalk. Because any such parcel could contain an explosive device, all unattended parcels must be regarded as potentially suspect.145
The fact that the regulation limits the “nature, extent [or] duration” of demonstrations conducted on the White House sidewalk does not necessarily render it unconstitutional; 146 the burden it imposes on expression must be weighed against the government’s substantial interest in presidential security and the safety of persons on the sidewalk. It is clear that the elderly, the handicapped and infirm, and those with young children to care for will still be able to engage in protest despite the regulation. Organizations (such as NOW) which stage vigils of extended duration will, in many instances, be able to accommodate the special needs of such participants through the use of “facilitators.”147 Such persons can supply demonstrators with the items they require either by carrying the items on their person or by bringing them across Pennsylvania Avenue from Lafayette Park. Even if an organization does not use facilitators or if a demonstrator is engaged in a lone vigil, we are convinced that protest of a meaningful duration will remain possible for any persons who would have been able to demonstrate before adoption of the regulations.
Conclusion
The regulations challenged here reflect the same variety of reasoned decisionmaking approved of by the Supreme Court in Clark v. Community for Creative Non-Violence and Regan v. Time. It is not the prerogative of this or any other court to question regulatory provisions affecting the time, place and manner of speech which lie within the zone of constitutionality prescribed by the first amendment. While the temptation to engage in judicial rulemaking may be powerful, our Constitution is best preserved by adherence to the proper judicial role.
Reversed.
. Robbins Tr. at 6-8, 12.
. See 48 Fed.Reg. 28058, 28058 (1983); N.Y. Times, 9 Dec. 1982, at Al, col. 1.
. The agencies initially considered a non-regulatory approach, Parr Tr. at 17, 20-22; J.A. 210-11, but rejected it because it did not adequately address security concerns, id.; Robbins Tr. at 18-22, 69-70.
. See 48 Fed.Reg. at 28058. On 23 April 1983, a ground-floor office in the Department of Justice building was firebombed. N.Y. Times, 25 Apr. 1983, at Al, col. 2. Three days later, a bomb concealed in a flowerpot exploded on the front steps of the National War College at Fort McNair. Id., 27 Apr. 1983, at A18, col. 4. On 18 October 1983, security officers at the Capitol apprehended a visitor to the House gallery who had concealed a homemade bomb under his shirt. Id., 2 Nov. 1983, at A22, col. 1. Less than a month later, a terrorist bomb exploded on the Senate side of the Capitol. Id., 8 Nov. 1983, at Al, col. 3.
The recent terrorist incidents have sparked increased concern for the protection of federal *1521buildings in Washington. Extensive security measures have been instituted at the Capitol in response to the November 1983 bombing. See N.Y. Times, 21 Jan. 1984, at 19, col. 1 (bulletproof steel plates installed in Members’ chairs on House floor); Wash. Post, 6 Jan. 1984, at A4, col. 1 (concrete barriers and new metal detectors); N.Y. Times, 9 Nov. 1983, at Al, col. 4 (new security regulations). Officials have taken similar steps to secure the State Department building, id., 18 Dec. 1983, § IV, at 1, col. 1 (concrete barriers), and the Pentagon, id., 21 July 1984, at 19, col. 2 (metal detectors); id., 17 Dec. 1983, at 9, col. 1 (closing of traffic tunnels under Pentagon).
The regulations challenged here are but one of a number of security measures recently taken to protect the White House and its occupants. Visitors who wish to tour the Mansion must now pass through a "garden pavillion,” where they are checked for guns and other weapons. Id., 18 Mar. 1983, at A15, col. 2; see also id., 17 Mar. 1984, at 12, col. 5 (new security measures for visitors and press). Workers have erected concrete barriers along the White House sidewalk to prevent "truck bombings” of the type that destroyed American installations in Lebanon. Id., 4 Jan. 1984, at B6, col. 2; id., 22 Dec. 1983, at A12, col. 1; id., 4 Dec. 1983, § I, at 31, col. 1.
. See 48 Fed.Reg. at 28058.
. 48 Fed.Reg. 17352 (1983).
. Id. at 17352. The interim regulations provided for public comment until 23 May 1983. Id.
. The White House sidewalk is defined as “the south sidewalk of Pennsylvania Avenue, N.W., between East and West Executive Avenues, NW.” 36 C.F.R. § 50.19(a)(5) (1983).
. 48 Fed.Reg. 17352 (1983).
. Id.
. The three were Edward Saffron, Conception Picciotto, and Robert Dorrough.
. Complaint for Declaratory Judgment and Injunctive Relief, reprinted in J.A. at 16-25. The National Organization for Women later intervened. White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 27 July 1983).
. 5 U.S.C. § 553(b)(B) (1982). See generally Jordan, The Administrative Procedure Act’s "Good Cause" Exemption, 36 Ad.L.Rev. 113 (1984) (surveying cases).
. White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 3 May 1983).
. Id. Judge Bryant later extended the injunction to 23 May 1983. White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 10 May 1983).
. 48 Fed.Reg. 22284 (1983) (proposed 17 May 1983).
. 48 Fed.Reg. 28058, 28059 (1983).
. 48 Fed.Reg. 28058 (1983). The regulations are codified at 36 C.F.R. §§ 50.7(h)(2), 50.-19(e)(9)-(10) (1983). In its preamble to the regulations, the Park Service stated that "[t]he need to address immediate security concerns in the White House area” constituted "good cause” for dispensing with the thirty-day delay period normally required before a new rule can become effective. 48 Fed.Reg. at 28058-59; see 5 U.S.C. § 553(d)(3) (1982) (good cause exception to thirty day delay requirement). The Park Service set 5 July as the date on which the regulations would become effective. Upon challenge by the plaintiffs, the district court held that the government had failed to substantiate its determination that good cause existed. White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 1 July 1983). In two successive temporary restraining orders, the court enjoined enforcement of the regulations until 17 July. Id.; White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 8 July 1983).
. Amended Complaint for Declaratory Judgment and Injunctive Relief, reprinted in J.A. at 31-38.
. 36 C.F.R. § 50.19(e)(9) (1983).
. The regulation uses the term “width,” id., but it is obvious that the reference is to the vertical dimension.
. Id.
. Id.
. Id. The three foot mark is readily identifiable because the pavement joints in the sidewalk occur every one and one-half feet from the fence. 48 Fed.Reg. at 28061. The second joint, therefore, marks the line established by the regulation.
. 36 C.F.R. § 50.19(e)(9) (1983).
. Id. ("ten yards on either side of the center point"). Unlike the three foot zone, see supra note 24, the center zone does not appear to be demarcated by actual landmarks on the sidewalk.
. 36 C.F.R. § 50.19(e)(9) (1983). In short, the regulations prohibit stationary, but not moving, protest within the center zone.
. 36 C.F.R. §§ 50.7(h)(2), 50.19(e)(10) (1983). Sections 50.7(h)(2) and 50.19(e)(10) are substantively identical.
. 48 Fed.Reg. at 28058.
. White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 19 July 1983) (order).
. White House Vigil for the ERA Comm. v. Watt, No. 83-1243, slip op. at 14 (D.D.C. 19 July 1983).
. Id. at 20.
. Id. at 17-18.
. Id. The regulation bars the placement of parcels on the sidewalk except "momentarily ... in the immediate presence of the owner.” 36 C.F.R. §§ 50.7(h)(2), 50.19(e)(10) (1983). The substantive effect of the district court’s order was to delete the word "momentarily” from the regulation. As a practical matter this is a change of significance. Guards can at once spot a package on the sidewalk. If it is not immediately picked up by its purported owner, under the original regulation the guards can move to seize it. Under the district court’s modification, the guards have no right to inspect or seize a parcel on the sidewalk; ten minutes after depositing it, the "owner” may be impossible to identify among the shifting crowds on the sidewalk. In a worst case scenario, the "owner” may be some distance away, running for his life. This is but one of many possible examples of why security experts are experts and judges are not.
. White House Vigil for the ERA Comm. v. Watt, No. 83-1243, slip op. at 16 (D.D.C. 19 July 1983).
. Id. at 20-21.
. White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 19 July 1983) (order). The prohibition of structures is a part of the parcels restriction.
. White House Vigil for the ERA Comm. v. Watt, 717 F.2d 568 (D.C.Cir.1983) (per curiam).
. Id. at 571; see Doran v. Salem Inn, Inc., 422 U.S. 922, 931-32, 95 S.Ct. 2561, 2567-68, 45 L.Ed.2d 648 (1975).
. White House Vigil, 717 F.2d at 572 (“[W]here the security of the President is involved, our decisions have established that we may modify a preliminary injunction in extreme circumstances even when there has been no abuse of discretion below.”); see A Quaker Action Group v. Hickel, 421 F.2d 1111, 1118-19 (D.C.Cir.1969).
. This court ordered the district court to modify its preliminary injunction in the following respects:
(1) A limit shall be set as to the size, number, and spacing of signs leaned against the White House fence or ledge, or placed in a stationary position within three feet of the fence, at any one time to the extent reasonably necessary to permit surveillance of both sides of the signs by a combination of officers stationed inside and outside the White House fence;
(2) Any sign or placard placed on the White House sidewalk, leaned against the White House fence, or placed upon or leaned against the ledge, shall be attended at all times by being within three feet of the person responsible for controlling it;
(3) Any sign support or frame made of hollow metal tubing shall be permanently secured at both ends in a manner which will prevent the insertion of any object into the tubing or the ejection of any object from the tubing;
(4) The regulations in 36 C.F.R. §§ 50.-19(e)(10) and 50.7(h)(2) pertaining to the placement or storage of parcels, containers, packages, bundles or other property on the White House sidewalk may be enforced. Any such enforcement shall be without distinction between demonstrators and others, and without prejudice to consideration by the District Court on remand of this Order, or in the plenary trial, of a claim for an exception to these requirements for the benefit of any plaintiff claiming a right to have on the White House sidewalk under the immediate physical control of that plaintiff a reasonable inventory of pamphlets, leaflets and similar writings for distribution there.
717 F.2d at 569-70.
. Id. at 569, 572.
. Id.
. Id.
. Id. at 569-70; see id. at 573.
. Id. at 570, 573. Nor do they constitute the law of the case. See United States v. United States Smelting Refining & Mining Co., 339 U.S. 186, 198-99, 70 S.Ct. 537, 544, 94 L.Ed. 750 (1950); Lewis v. Creasey Corp., 198 Ky. 409, 413, 248 S.W. 1046, 1048 (1923).
. White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 23 Aug. 1983). The district court originally set 20 September as the trial date. Id. Appellees indicated to the court that they would not be able to prepare for trial on such short notice. The court refused to grant an extension of time unless appellees agreed to the vacating of the preliminary injunction. Over intervenor NOW's objections, appellees agreed “with great reluctance” to the arrangement. Motion to Vacate Preliminary Injunction and to Reschedule Trial, reprinted in J.A. at 113-15. The district court set 6 December as the new trial date. White House Vigil for the ERA Comm. v. Watt, No. 83-1243 (D.D.C. 2 Sept. 1983).
. They included Jerry S. Parr, the Assistant Director of the Office of Protective Research, United States Secret Service; Edward P. Walsh, the Deputy Assistant Director of the same office; John B. Flinn, Chief of the Munitions Countermeasures Section, Technical Security Division *1525of the same office; and James C. Lindsey, Deputy Chief (Operations) of the Park Police.
. White House Vigil for the ERA Comm. v. Clark, No. 83-1243 (D.D.C. 26 Apr. 1984).
. Id., slip op. at 18 (emphasis in original).
. Id. at 20-21.
. Id. at 21.
. Id.
. Id. at 23.
. Id. at 24.
. Id.
. Id. at 25. The court’s characterization of the center zone restriction was directly at odds with its earlier discussion of the provision. In its opinion of 19 July 1983, the court had noted that
[t]he defendants have been somewhat timid in advancing aesthetic considerations to support the regulations. However, the court has no difficulty in accepting that such considerations are legitimate: visitors to the Nation’s Capital are entitled to a clear view of the sights they come from such great distances to see. The court accordingly finds no objection to the special restrictions which the regulations place on the use of the central portion of the sidewalk. The court agrees with the defendants that a 20-yard restricted zone is not unreasonable given that the total length of the sidewalk exceeds 700 feet.
White House Vigil for the ERA Comm. v. Watt, No. 83-1243, slip op. at 20-21 (D.D.C. 19 July 1983).
. White House Vigil for the ERA Comm. v. Clark, No. 83-1243, slip op. at 26 (D.D.C. 26 Apr. 1984).
. The specific first amendment right relied upon by the district court was not the free speech guarantee, but rather the right of petition and assembly. Id. at 19; see U.S. Const. amend. I (“Congress shall make no law ... abridging ... the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.”).
. Defendant’s Post-Trial Brief at 66, quoted in White House Vigil for the ERA Comm. v. Clark, No. 83-1243, slip op. at 19 (D.D.C. 26 Apr. 1984).
. White House Vigil, slip op. at 19.
. White House Vigil for the ERA Comm. v. Clark, No. 83-1243 (D.D.C. 26 Apr. 1984) (order).
. Id.
. Id.
. Regan v. Time, Inc., — U.S.-, 104 S.Ct. 3262, 82 L.Ed.2d 487 (1984); Clark v. Community for Creative Non-Violence, — U.S.-, 104 S.Ct. 3065, 82 L.Ed.2d 221 (1984).
. See Perry Educ. Ass’n v. Perry Local Educators’ Ass’n, 460 U.S. 37, 45, 103 S.Ct. 948, 954, 74 L.Ed.2d 794 (1983). The classic statement of the public forum doctrine is found in Justice Roberts’s opinion in Hague v. CIO, 307 U.S. 496, 59 S.Ct. 954, 83 L.Ed. 1423 (1939):
Wherever the title of streets and parks may rest, they have immemorially been held in trust for the use of the public and, time out of mind, have been used for purposes of assembly, communicating thoughts between citizens, and discussing public questions. Such use of the streets and public places has, from ancient times, been a part of the privileges, immunities, rights, and liberties of citizens. The privilege of a citizen of the United States to use the streets and parks for communication of views on national questions may be regulated in the interest of all; it is not absolute, but relative, and must be exercised in subordination to the general comfort and convenience, and in consonance with peace and good order; but it must not, in the guise of regulation, be abridged or denied.
307 U.S. at 515-16, 59 S.Ct. at 964.
While the government may not prohibit all .communicative activity in a public forum, it may enforce a content-based exclusion if the regulation is necessary to serve a compelling state interest and is narrowly drawn to achieve that end. Perry Educ. Ass’n, 460 U.S. at 45, 103 S.Ct. at 954. The government has not attempted to impose such an exclusion in the present case.
. See A Quaker Action Group v. Morton, 516 F.2d 717, 724-25 (D.C.Cir.1975); cf. United States v. Grace, 461 U.S. 171, 103 S.Ct. 1702, 1708, 75 L.Ed.2d 736 (1983) (sidewalk in front of Supreme Court, like other public sidewalks, is a public forum).
. Hague v. CIO, 307 U.S. at 515, 59 S.Ct. at 964; see United States v. Grace, 103 S.Ct. at 1708.
. United States v. Grace, 103 S.Ct. at 1708.
. Hague v. CIO, 307 U.S. at 515-16, 59 S.Ct. at 964.
. See Regan v. Time, 104 S.Ct. at 3266-67; Clark v. Community for Creative Non-Violence, — U.S.-, 104 S.Ct. at 3069; Members of the City Council of Los Angeles v. Taxpayers for Vincent, — U.S.-, 104 S.Ct. 2118, 2129, 80 L.Ed.2d 772 (1984); United States v. Grace, 103 S.Ct. at 1707; Perry Educ. Ass'n, 460 U.S. at 45, 103 S.Ct. at 954; Heffron v. International Soc’y for Krishna Consciousness, Inc., 452 U.S. 640, 647-48, 101 S.Ct. 2559, 2563-64, 69 L.Ed.2d 298 (1981); United States v. O’Brien, 391 U.S. 367, 377, 88 S.Ct. 1673, 1679, 20 L.Ed.2d 672 (1968).
. Consolidated Edison Co. v. Public Serv. Comm’n, 447 U.S. 530, 536, 100 S.Ct. 2326, 2332, 65 L.Ed.2d 319 (1980).
. Note from James G. Watt to Moody Tidwell (13 Jan. 1983), reprinted in J.A. at 174.
. Robbins Tr. at 112.
. See supra note 66.
. 48 Fed.Reg. 28058, 28061 (1983).
. See Regan v. Time, 104 S.Ct. 3262; Clark v. Community for Creative Non-Violence, 104 S.Ct. 3065; Taxpayers for Vincent, 104 S.Ct. 2118.
. See, e.g., Watts v. United States, 394 U.S. 705, 707, 89 S.Ct. 1399, 1401, 22 L.Ed.2d 664 (1969); White House Vigil for the ERA Comm. v. Watt, 717 F.2d 568, 570, 572 (D.C.Cir.1983) (per curiam); A Quaker Action Group v. Morton, 516 F.2d at 729; A Quaker Action Group v. Hickel, 421 F.2d 1111, 1117 (D.C.Cir.1969).
. See Heffron v. International Soc’y for Krishna Consciousness, Inc., 452 U.S. 640, 101 S.Ct. 2559, 69 L.Ed.2d 298 (1981); Cox v. New Hampshire, 312 U.S. 569, 574, 576, 61 S.Ct. 762, 765, 85 L.Ed. 1049 (1941).
. See Taxpayers for Vincent, 104 S.Ct. at 2129-30; Metromedia, Inc. v. City of San Diego, 453 U.S. 490, 507-08, 101 S.Ct. 2882, 2892, 69 L.Ed.2d 800 (1981); Berman v. Parker, 348 U.S. 26, 75 S.Ct. 98, 99 L.Ed. 27 (1954).
. We feel constrained to point out an ambiguity in the Supreme Court’s latest formulation of the "time, place and manner" test. In Regan v. Time, the Court recited the standard requirements of content-neutrality and alternative channels of communication, but stated only that a regulation "must 'serve a significant governmental interest.’ ” 104 S.Ct. at 3266-67 (quoting Heffron, 452 U.S. at 649, 101 S.Ct. at 2565). No reference is made to the requirement that the regulation be narrowly tailored. We decline to interpret Regan and Heffron as establishing a more lenient stándard than that followed by the Court in other recent cases. Had the Court meant to alter the test which it had recognized only four days earlier in Clark v. Community for Creative Non-Violence, we believe that it would have done so in a more explicit fashion.
. The "clearly erroneous” standard is set forth in Fed.R-Civ.P. 52(a).
. One reason for judicial lack of expertise: courts are not in a position to evaluate the feasibility of administration and enforcement of regulations, as are the agencies, who are therefore properly charged with drafting them. This is demonstrated by the impracticality of some of the "finetuning" done by the district court. See, e.g., supra note 34.
. 104 S.Ct. 3065 (1984).
. Community for Creative Non-Violence v. Watt, 703 F.2d 586 (1983) (en banc) (per curiam).
. Clark v. Community for Creative Non-Violence, 104 S.Ct. 3065.
. Id. at 3068-69.
. Id. at 3070.
. Id. at 3069-72; see id. at 3071 (“If the Government has a legitimate interest in ensuring that the National Parks are adequately protected, which we think it has, and if the parks would be more exposed to harm without the sleeping prohibition than with it, the ban is safe from invalidation under the First Amendment as a reasonable .regulation on the manner in which a demonstration may be carried out.”).
. Id. at 3072.
The concurrence-dissent relies on the brief passage in which the Court notes that proposed alternatives “would still curtail the total allowable expression in which demonstrators could engage." Id. at 3072, quoted in Op. at 1545. From this the concurrence-dissent concludes that Clark stands for the following proposition: “a challenger to a time, place, and manner restriction cannot win by merely conjuring up an alternative regulation that does not prohibit its conduct, regardless of the alternative regulation’s effects on the expression of others.” Op. at 1546 (emphasis in original). This interpretation is unnecessarily restrictive. There is nothing in Justice White’s majority opinion to suggest that he intended the quoted passage to limit or qualify his analysis.
. 104 S.Ct. 3262 (1984).
. Id. at 3271-72. The Court struck down a provision which specified legitimate purposes for which photographs might be published. Id. at 3267.
. Id. at 3271-72 (plurality).
The concurrence-dissent's interpretation of Justice White’s opinion is unjustifiably narrow. Judge Wald contends that Justice White qualified his explicit rejection of less-restrictive-alternative analysis in a footnote, in which he wrote that ”[i]f Time is exempted from the color requirement, so must all others who wish to use such reproductions. While Time may consistently use negatives and plates that are of little use to counterfeiters, there is no way of ensuring that others will adhere to that practice." Id. at 3272 n. 12. From this passage Judge Wald derives the principle that "[a] time, place, and manner regulation is not unconstitutional as applied to situations that do not threaten the governmental interest at stake if that application is an unavoidable consequence of regulating other conduct that does threaten the interest at stake." Op. at 1544 (emphasis in original). According to the opinion, Regan stands for this and nothing more. What the opinion fails to mention, however, is that Justice White was merely applying in his footnote the familiar principle that “the effectiveness of [a] regulation should not be measured solely by the adverse consequences of exempting a particular plaintiff from the regulation.” 104 S.Ct. at 3272 n. 12 (citing Clark, 104 S.Ct. 3065, 3070-71; Heffron v. International Soc'y for Krishna Consciousness, Inc., 452 U.S. 640, 652-53, 101 S.Ct. 2559, 2566, 69 L.Ed.2d 298 (1981)). In short, Justice White's footnote does not limit or qualify his textual discussion because the two passages deal with completely different constitutional principles.
. 104 S.Ct. at 3296 (Stevens, J., concurring in part and dissenting in part).
. Like the "zone of reasonableness" in administrative law, the zone of constitutionality is "an abstract quality represented by an area rather than a pinpoint.” Montana-Dakota Utils. Co. v. Northwestern Pub. Serv. Co., 341 U.S. 246, 251, 71 S.Ct. 692, 695, 95 L.Ed. 912 (1951).
. Judge Wald praises the district court for engaging in a de novo review of factors underlying the challenged regulations. Such a review she finds consistent with this court’s earlier decision in A Quaker Action Group v. Morton, 516 F.2d 717 (D.C.Cir.1975); see Op. at 1542-1543. Whether Judge Wald’s reading of that case is correct or not, judicial review of time, place and manner restrictions must now proceed under the framework established by the Supreme Court in Clark and Regan. See Clark, 104 S.Ct. at 3072 (time, place, and manner decisions do not assign to the judiciary the authority to replace the Park Service as the manager of the, Nation's parks), quoted supra pp. 1552-1553.
It is axiomatic that government regulations which restrict the exercise of free speech are subject to closer scrutiny than other types of administrative decisions, and that courts, not agencies, are the ultimate arbiters of constitutionality. It by no means follows, however, that courts are required or permitted to duplicate the extensive factual inquiries undertaken by agencies when they draft regulations. Not only is such duplication highly inefficient, it reflects a lack of judicial respect for the unique expertise of administrative agencies. The agency may as well not have engaged in exhaustive and detailed fact-finding if a court before which the agency's regulation is challenged takes it upon itself to do the same thing de novo.
. We agree with Judge Wald that Clark and Regan "refine but do not revamp settled principles in first amendment law.” Op. at 1542. What those decisions do is establish once and for all that least-restrictive-alternative analysis is not a part of the constitutional inquiry for determining the validity of time, place and manner restrictions. Because the Supreme Court has never considered that analysis to be an integral element of the constitutional test, see Regan, — U.S.-, 104 S.Ct. 3262, 3271-72, 82 L.Ed.2d 487 (plurality), Clark and Regan settle but do not revamp first amendment law. The "zone of constitutionality” analysis which we adopt today is nothing more or less than the doctrinal reverse of least-restrictive-alternative analysis. Only if one incorrectly assumes that the latter form of analysis was historically a part of the time, place and manner test can one conclude, as Judge Wald does, that our approach accords the government "greater latitude than previously to burden protected expression.” Op. at 1542.
Judge Wald also contends that United States v. Grace, 461 U.S. 171, 103 S.Ct. 1702, 75 L.Ed.2d 736 (1984), sanctions the result reached by the district court in the present case. Op. at 1546. The challenged statute in Grace prohibited the "display [of] ... any flag, banner, or device designed or adapted to bring into public notice any party, organization, or movement,” in the "Supreme Court Building or grounds.” 40 U.S.C. § 13k (1982). The Supreme Court *1532grounds encompassed, inter alia, the public sidewalks surrounding the Court'building, see 40 U.S.C. § 13p (1982); those sidewalks are a public forum, Grace, 103 S.Ct. at 1708. Because the statutory restriction did not substantially serve the government's interests, the Court held that the statute was unconstitutional as applied to the sidewalks, id. at 1708-10, even though the statute did not specifically distinguish between the sidewalks and other parts of the Supreme Court grounds. Judge Wald’s opinion equates the Court’s decision in Grace to focus exclusively on public sidewalks with the district court's creation of a "five foot rule” for parcel and sign placement in the present case, concluding that ”[i]f one was ‘rewriting,’ so was the other." Op. at 1547. This fails to appreciate, however, the crucial distinction between what the Supreme Court did in Grace and what the district court did here. The reason the Grace Court considered § 13k exclusively in the context of public sidewalks was that it could thereby avoid a needless constitutional inquiry into the status of the other parts of the Supreme Court grounds and building. There was no need to determine whether those areas were also public forums, because "the controversy presented by appellees concerned their right to use the public sidewalks." 103 S.Ct. at 1706 (emphasis added). Early in its opinion, therefore, the Court stated that it would "address only whether the proscriptions of § 13k are constitutional as applied to the public sidewalks." Id.
It is beyond dispute that courts are permitted to assess the constitutionality of a statute or regulation by drawing distinctions that are not explicitly embraced within the text of the provision. What courts may not do is substitute their factual judgment for that of the politically responsible body when that institution’s judgment lies within the parameters of first amendment constitutionality. The district court here did precisely that when it arbitrarily rewrote the Park Service’s regulations. The difference between Grace and the district court’s opinion is therefore not only great, it is of constitutional dimensions.
. See 36 C.F.R. § 50.19(e)(9) (1983).
. White House Vigil for the ERA Comm. v. Clark, No. 83-1243 (D.D.C. 26 Apr. 1984) (order).
. Id.
. 48 Fed.Reg. 28058, 28058 (1983). Those interests include pedestrian safety and traffic and the preservation of the White House view.
. A Quaker Action Group v. Hickel, 421 F.2d 1111, 1117 (D.C.Cir.1969); see also Watts v. United States, 394 U.S. 705, 707, 89 S.Ct. 1399, 1401, 22 L.Ed.2d 664 (1969) (“The Nation undoubtedly has a valid, even an overwhelming, interest in protecting the safety of its Chief Executive and in allowing him to perform his duties without interference from threats of physical violence”); White House Vigil for the ERA Comm. v. Watt, 717 F.2d 568, 570 (D.C.Cir.1983) (“ ‘peculiar sensitivity of ... the safety of the President’ ”).
. A Quaker Action Group v. Morton, 516 F.2d 717, 729 (D.C.Cir.1975).
. Id. at 725.
. The twelfth story of a recently-completed office building on 15th Street enjoys a “nearly unobstructed view" of the North Portico of the White House. Wash. Post, 12 Sept. 1984, at C6, col. 1. The Secret Service has reached an agreement with the building’s developer which will permit the Service to post agents on the rooftop during special White House events and to oversee the building’s security system. Id.
. There is no suggestion, of course, that appellees or intervenors themselves would engage in activity that threatens the White House or its occupants. So far as the record shows, their demonstrations have always been conducted in a peaceful and orderly fashion. We are concerned instead with persons who harbor less beneficient intentions. See Heffron v. International Soc'y for Krishna Consciousness, Inc., 452 U.S. 640, 652, 101 S.Ct. 2559, 2566, 69 L.Ed.2d 298 (1981) (justification for regulation should not be measured solely with regard to activities of persons before court).
. The district court erred when it required the government to demonstrate a “probable danger" arising from the regulated activity. White House Vigil for the ERA Comm. v. Clark, No. 83-1243, slip op. at 18 (D.D.C. 26 Apr. 1984) (emphasis in original). Counsel for appellees conceded as much at oral argument. Agencies charged with the protection of the President must be permitted, within reason, to anticipate novel security threats and to act to avert them. Common sense and the experience of history recommend no less. See A Quaker Action Group v. Morton, 362 F.Supp. 1161, 1169 (D.D.C. 1973) (“No President was ever killed in a theatre until Lincoln, in a railway station until Garfield, in a reception line until McKinley, or in an open car until Kennedy.”), modified, 516 F.2d 717 (D.C.Cir.1975).
. 36 C.F.R. § 50.19(e)(9) (1983).
. See 48 Fed.Reg. 28058, 28058 (1983). Tourists and passersby are not the only beneficiaries of the center zone restriction. To the extent the news media publishes or broadcasts images of the White House, millions of Americans benefit.
. Berman v. Parker, 348 U.S. 26, 33, 75 S.Ct. 98, 102, 99 L.Ed. 27 (1954) (“It is within the power of the legislature to determine that the community should be beautiful as well as healthy, spacious as well as clean, well-balanced as well as carefully patrolled.”).
The governmental regulation of aesthetics has generated a considerable body of legal scholarship. Representative pieces include Anderson, Architectural Controls, 12 Syracuse L.Rev. 26 (1960); Aronovsky, Metromedia, Inc. v. City of San Diego: Aesthetics, the First Amendment, and the Realities of Billboard Control, 9 Ecology L.Q. 295 (1981); Bufford, Beyond the Eye of the Be*1535holder: A New Majority of Jurisdictions Authorize Aesthetic Regulations, 48 UMKC L.Rev. 125 (1980); Costonis, Law and Aesthetics: A Critique and a Reformulation of the Dilemmas, 80 Mich. L.Rev. 355 (1982); Crumplar, Architectural Controls: Aesthetic Regulation of the Urban Environment, 6 UrbXaw. 622 (1974); Dukeminier, Zoning for Aesthetic Objectives: A Reappraisal, 20 Law & Contemp.Probs. 218 (1955); Michelman, Toward a Practical Standard for Aesthetic Regulation, 15 PracXaw. 36 (1969); Rowlett, Aesthetic Regulation Under the Police Power: The New General Welfare and the Presumption of Constitutionality, 7 Wake Forest L.Rev. 230 (1971); Williams, Subjectivity, Expression, and Privacy: Problems of Aesthetic Regulation, 62 MinnX.Rev. 1 (1977); Comment, Zoning, Aesthetics, and the First Amendment, 64 ColumX.Rev. 81 (1964); Comment, The Reasonableness of Aesthetic Zoning in Florida: A Look Beyond the Police Power, 10 Fla.St.U.L.Rev. 441 (1982); Note, Aesthetics and the Constitution: Houston’s Sign Ordinance, 18 HousX.Rev. 629 (1981); Note, Beyond the Eye of the Beholder: Aesthetics and Objectivity, 71 MichX.Rev. 1438 (1973); Note, Aesthetic Nuisance: An Emerging Cause of Action, 45 N.Y. U.L.Rev. 1075 (1970); Note, Architecture, Aesthetic Zoning, and the First Amendment, 28 Stan.L. Rev. 179 (1975); Note, Aesthetic Regulation and the First Amendment, 3 VaJ.Nat.Resources L. 237 (1984).
. See generally Note, Local Historic Preservation Measures as an Alternative to Federal Preservation Efforts, 3 VaJ.Nat.Resources L. 263 (1984) (recent survey of historic preservation cases).
. In Metromedia, Inc. v. City of San Diego, 453 U.S. 490, 101 S.Ct. 2882, 69 L.Ed.2d 800 (1981), the Court struck down a municipal ordinance which imposed strict prohibitions on the erection of outdoor billboards. All of the Justices agreed, however, that purely aesthetic considerations may justify restrictions on speech. 453 U.S. at 507-08, 510, 101 S.Ct. at 2892, 2893 (White, J., for the plurality); id. at 530-34, 101 S.Ct. at 2904-06 (Brennan, J., concurring in judgment); id. at 550, 551 n. 23, 552, 101 S.Ct. at 2914, 2915 n. 23, 2915 (Stevens, J., dissenting in part); id. at 559-61 (Burger, C.J., dissenting); id. at 570, 101 S.Ct. at 2924 (Rehnquist, J., dissenting).
The Court reaffirmed the proposition in Members of the City Council of Los Angeles v. Taxpayers for Vincent, — U.S.-, 104 S.Ct. 2118, 80 L.Ed.2d 772 (1984). There it upheld a municipal ordinance prohibiting the posting of signs on public property. Justice Stevens wrote for the majority that
[tjhe problem addressed by this ordinance— the visual assault on the citizens of Los Angeles presented by an accumulation of signs posted on public property — constitutes a significant substantive evil within the City's power to prohibit. "[T]he city’s interest in attempting to preserve [or improve] the quality of urban life is one that must be accorded high respect.”
104 S.Ct. at 2130 (quoting Young v. American Mini Theatres, Inc., 427 U.S. 50, 71, 96 S.Ct. 2440, 2452, 49 L.Ed.2d 310 (1976)).
Appellees attempt to distinguish Taxpayers for Vincent on the ground that it concerned the long-term display of unattended signs, rather than face-to-face communicative activity of the type involved here. It is true that Justice Stevens, in his majority opinion, used words to that effect in the course of distinguishing Schneider v. State, 308 U.S. 147, 60 S.Ct. 146, 84 L.Ed. 155 (1939); see Taxpayers for Vincent, 104 S.Ct. at 2131. The Court in Schneider struck down an ordinance that prohibited handbilling on the streets; it held that the municipality's aesthetic interest in avoiding litter could have been protected through an ordinance which penalized persons who actually litter. We believe, however, that the basis of Justice Stevens’s discussion of Schneider is not the distinction urged by appellees, but rather the distinction explicitly adopted by the Justice in another passage of his opinion;
With respect to signs posted by appellees ... it is the tangible medium of expressing the message that has the adverse impact on the appearance of the landscape. In Schneider, an anti-littering statute could have addressed the substantive evil without prohibiting expressive activity, whereas application of the prophylactic rule actually employed gratuitously infringed upon the right of an individual to communicate directly with a willing listener. Here, the substantive evil — visual blight — is not merely a possible by-product of the activity, but is created by the medium of expression itself. In contrast to Schneider, therefore, the application of ordinance in this case responds precisely to the substantive problem which legitimately concerns the City. *1536The ordinance curtails no more speech than is necessary to accomplish its purpose.
104 S.Ct. at 2132. The visual blight in the present case is "created by the medium of expression itself" — stationary protests within the center zone, which obstruct the view of the White House and its grounds. The conduct addressed by the Park Service regulations is therefore more like that proscribed by the municipal ordinance in Taxpayers for Vincent than that proscribed by the ordinance in Schneider.
. Metromedia, 453 U.S. at 510, 101 S.Ct. at 2894.
. One notable example outside the first amendment context is the adoption of Maya Lin's design for the Vietnam Veterans' Memorial in Washington, D.C. Compare Wolfe, Art Disputes War: The Battle of the Vietnam Memorial, Wash.Post, 13 Oct. 1982, at Bl, col. 4 (criticizing design), with Goldberger, Vietnam Memorial: Questions of Architecture, N.Y. Times, 7 Oct. 1982, at C25, col. 1 (praising design).
. Judge Wald’s opinion questions the utility of our distinction between aesthetic regulations which enact societal preferences and those which enact the preferences of individual government officials. Such a distinction, Judge Wald suggests, may run afoul of the principle that the first amendment protects unpopular minorities from the prejudices of hostile majorities. Op. at 1551. The approach we adopt today, however, is not blind to the fact that majority tastes sometimes mask disapproval of the substantive content of expressive activities. Our analysis does nothing to alter the familiar proscription of content-based restrictions. See supra pp. 1549-1550. That element of the constitutional test applies with unqualified force to government regulations which derive their ostensible legitimacy from the aesthetic preferences of popular majorities.
. See Metromedia, 453 U.S. at 5t0, 101 S.Ct. at 2894 (one consideration is whether the aesthetic judgment is so unusual as to raise suspicions in itself).
. "Aesthetically pleasing" in this context refers not so much to that which is considered visually beautiful as to that which promotes or enhances the culturar identity of an area. The debate over the "White House experience” is essentially a debate over cultural identity; as such, it is more susceptible to objective resolution than a disagreement over which of two views is more "pleasant" or "beautiful.” See Costonis, supra note 110.
It is not at all clear why appellees and intervenors regard stationary protest within the center zone as essential to the White House experience. Surely the additional cultural significance of stationary protest over mobile protest is, at most, insignificant. The government’s decision to allow only mobile protest within the zone enhances the White House experience for many (and perhaps most) tourists, while it diminishes that experience for other tourists in only an insubstantial and indirect fashion.
. The concurrence-dissent contends that the center zone restriction is unnecessary to further the government’s aesthetic interests; in doing so, however, the opinion seriously underestimates the degree to which stationary demonstrations within the center zone have the potential to obscure the view of the White House. While the size restrictions and the prohibition on unattended signs reduce that potential to some extent, a proliferation of hand-held signs of legal dimensions may well obscure a significant portion of the White House view. For example, the height limitation applies only to signs themselves and not to their supports; some signs may therefore be considerably higher than others. Because different signs can obscure different levels of view, the cumulative effect may be to block vision for a significant range of height above the sidewalk. Such problems are far less pronounced when demonstrators are required to remain moving within the center zone: stationary signs have the potential of blocking considerably more of the White House view than do mobile signs.
Nor is it any mystery why the Park Service decided to allow non-stationary protests within the center zone, even though such protests will admittedly obscure some of the White House view. Assuming arguendo that a ban on non-stationary protests would have been constitutional, the effect of instituting such a ban would be to demarcate a “no man’s land” in the middle of the sidewalk. Protestors on either side of the zone would have considerable difficulty communicating with one another, for they would be prohibited from carrying their signs across the demarcated area. The regulation the Park Service adopted represents a reasonable effort to accommodate the needs of such protestors.
. 506 F.2d 53 (D.C.Cir.1974) (per curiam).
. Id. at 58; see also Heffron v. International Soc’y for Krishna Consciousness, Inc., 452 U.S. 640, 647, 101 S.Ct. 2559, 2563, 69 L.Ed.2d 298 (1981) (first amendment does not guarantee right to communicate one's views at all times and places or in any manner that may be desired); Community for Creative Non-Violence v. Watt, 703 F.2d 586, 618-19 (D.C.Cir.1983) (en banc) (Wilkey, J., dissenting) (first amendment does not guarantee right to deliver message in the most effective manner possible, nor does it guarantee media attention), rev'd, — U.S.-, 104 S.Ct. 3065, 82 L.Ed.2d 221 (1984); Concerned Jewish Youth v. McGuire, 621 F.2d 471, 474 (2d Cir.1980) (first amendment; does not guarantee news publicity), cert. denied, 450 U.S. 913, 101 S.Ct. 1352, 67 L.Ed.2d 337 (1981); United States v. Kiger, 297 F.Supp. 339, 343-44 (S.D.N.Y.1969) (first amendment does not protect violation of a criminal statute in order to get one's views carried in the press and on the air), aff'd per curiam, 421 F.2d 1396 (2d Cir.), cert. denied, 398 U.S. 904, 90 S.Ct. 1693, 26 L.Ed.2d 63 (1970).
. The fact that the regulations permit stationary protest outside the center zone does not suggest that the center zone restriction is a regulatory aberration. The decision to set aside only the central twenty yards of the sidewalk represents a healthy compromise between the interests of those who wish to view the White House and those who wish to demonstrate on the sidewalk.
. 36 C.F.R. §§ 50.7(h)(2), 50.19(e)(10) (1983).
. White House Vigil for the ERA Comm. v. Clark, No. 83-1243, slip op. at 26 (D.D.C. 26 Apr. 1984).
. White House Vigil for the ERA Comm. v. Clark, No. 83-1243 (D.D.C. 26 Apr. 1984) (order).
. Brief of Appellees at 54. Appellees do not suggest that we invalidate the parcels restriction in its entirety; indeed, such an argument would run counter to their consistent reliance on Rule 52(a).
. Brief for Appellants at 42-43.
. Appellees concede that the first amendment is not directly implicated by the parcels restriction. See Brief of Appellees at 50 (“the mere carrying or setting down of parcels on the White House sidewalk may not itself be squarely within the protection of [the] First Amendment”). So, too, does the district court. See White House Vigil for the ERA Comm. v. Clark, No. 83-1243, slip op. at 26 (D.D.C. 26 Apr. 1984) ("the placing of such containers on the sidewalk near a demonstrator cannot be characterized as a first amendment activity per se”).
. See, e.g., Spence v. Washington, 418 U.S. 405, 409-11, 94 S.Ct. 2727, 2729-30, 41 L.Ed.2d 842 (1974) (per curiam). A number of constitutional scholars have questioned the utility of a rigid distinction between speech and conduct. See, e.g., Baker, Scope of the First Amendment Freedom of Speech, 25 U.C.L.A. L.Rev. 964, 1010 (1978); Ely, Flag Desecration: A Case Study in the Roles of Categorization and Balancing in First Amendment Analysis, 88 Harv.L.Rev. 1482, 1495 (1975); Henkin, The Supreme Court, 1967 Term — Foreward: On Drawing Lines, 82 Harv.L. Rev. 63, 79 (1968).
. United States v. O'Brien, 391 U.S. 367, 376, 88 S.Ct. 1673, 1678, 20 L.Ed.2d 672 (1968).
. Moreover, the intent must be that of conveying a “particularized message.” Spence v. Washington, 418 U.S. at 410-11, 94 S.Ct. at 2730.
. Id. at 411, 94 S.Ct. at 2730.
. See, e.g., Edwards v. South Carolina, 372 U.S. 229, 83 S.Ct. 680, 9 L.Ed.2d 697 (1963).
. See, e.g., Shuttlesworth v. City of Birmingham, 394 U.S. 147, 89 S.Ct. 935, 22 L.Ed.2d 162 (1969).
. See, e.g., Thornhill v. Alabama, 310 U.S. 88, 60 S.Ct. 736, 84 L.Ed. 1093 (1940).
. See, e.g., Tinker v. Des Moines Indep. Community School Dist., 393 U.S. 503, 89 S.Ct. 733, 21 L.Ed.2d 731 (1969).
. See, e.g., Schneider v. State, 308 U.S. 147, 60 S.Ct. 146, 84 L.Ed. 155 (1939).
. See, e.g., Spence v. Washington, 418 U.S. 405, 94 S.Ct. 2727, 41 L.Ed.2d 842 (1974) (per curiam).
. In Community for Creative Non-Violence v. Watt, 703 F.2d 586 (D.C.Cir.1983) (en banc) (per curiam), rev'd, — U.S.-, 104 S.Ct. 3065, 82 L.Ed.2d 221 (1984), this court held that sleeping can, in certain circumstances, be "speech" within the meaning of the first amendment. The Supreme Court reversed on the grounds that the challenged regulation was a reasonable time, place and manner restriction. In doing so, the Court assumed, but did not decide, that sleeping may be expressive conduct. 104 S.Ct. at 3068-69. Because the Court was able to resolve the case on other grounds, the constitutional status of sleep remains uncertain. No matter how the issue is finally resolved, however, it is clear that the overnight sleeping at issue in CCNV lies much nearer the scope of constitutional protection than the placing of parcels on the White House sidewalk.
. Spence v. Washington, 418 U.S. at 410-11, 94 S.Ct. at 2730.
. Id. at 411, 94 S.Ct. at 2730. Onlookers would, of course, regard many other elements of the typical White House vigil as communicative. But the fact that demonstrating, chanting, or carrying signs is inherently expressive does not mean that the depositing of parcels on the sidewalks is as well. Because the regulations deal with segregable activities, so, too, must our analysis.
. It is clear that the Park Service did not intend for the parcels restriction to apply to signs or banners. See White House Vigil for the ERA Comm. v. Watt, No. 83-1243, slip op. at 6 n. 5 (D.D.C. 19 July 1983); 48 Fed.Reg. 28058, 28059 (1983). Demonstrators may place signs on the sidewalk so long as they maintain physical contact with them. See 36 C.F.R. § 50.-19(e)(9) (1983) (physical contact requirement).
Our decision should not be read as holding that activity of the type engaged in here is inherently non-expressive. In other circumstances the placing of items on the ground may be considered expression; we hold only that the demonstrators here have failed to establish the expressive content of their activity. See Clark v. Community for Creative Non-Violence, 104 S.Ct. at 3069 n. 5.
. Cf. id. at 3070 ("[Although we have assumed for present purposes that the sleeping banned in this case would have an expressive element, it is evident that its major value to this demonstration would be facilitative.”).
. This is a corollary of the principle that the first amendment protects expression rather than all human activities.
. Justice Marshall proposed a test in his dissenting opinion in Clark v. Community for Creative Non-Violence: “[Fjacilitative conduct that is closely related to expressive activity is itself protected by First Amendment considerations." 104 S.Ct. at 3077 n. 7 (Marshall, J., dissenting) (emphasis added). Besides the fact that Justice Marshall’s test was proposed in dissent and therefore carries no precedential weight, a “close relationship” standard would be too amorphous for objective application. Moreover, Justice Marshall would apparently apply the first amendment to some restrictions of facilitative activity that have no effect on expression itself; this result runs counter to the fundamental principle that expression is what is protected by the first amendment.
. The district court’s modification, allowing parcels to be placed on the sidewalk if the owner remains within five feet of them, must be rejected not only because it constitutes impermissible "finetuning” of the regulatory mechanism, but also because it is more arbitrary and less effective than the original provision. A rule which prohibits any deposit of parcels on the sidewalk, except momentarily, is capable of being easily enforced. It requires the presence of a relatively small number of police officers, thereby avoiding the perception that the White House is an “armed enclave.” Most importantly, it establishes a clear, bright line rule that does not lend itself to arbitrary or discriminatory enforcement.
By contrast, the district court’s modification would be difficult to enforce in an effective and even-handed manner. It would require police officers to ascertain both whether a parcel is located within five feet of a demonstrator and whether that demonstrator is its "owner.” One envisions a contingent of Park Police with tape measures in hand, dutifully attempting to comply with the district court’s order.
. See Clark v. Community for Creative Non-Violence, 104 S.Ct. at 3070-71.
. See Collins Tr. at 76, 127-32 (use of facilitators by NOW).