delivered the opinion of the Court.
The Secretary of Labor brought this action in the District Court for the Southern District of Indiana under § 402 (b) of the Labor-Management Reporting and Disclosure Act of 1959 (LMRDA), 73 Stat. 534, 29 U. S. C. § 482 (b), to invalidate the 1970 election of officers of Local 3489, United Steelworkers of America. The Secretary alleged that a provision of the Steelworkers’ International constitution, binding on the Local, that limits eligibility for local union office to members who have attended at least one-half of the regular meetings of the Local for three years previous to the election (unless pre*307vented by union activities or working hours),1 violated § 401 (e) of the LMRDA, 29 U. S. C. §481 (e).2 The District Court dismissed the complaint, finding no violation of the Act. The Court of Appeals for the Seventh Circuit reversed. 520 F. 2d 516 (1975). We granted certiorari to resolve a conflict among Circuits over whether the Steelworkers’ constitutional provision violates § 401 (e).3 424 U. S. 907 (1976). We affirm.
I
At the time of the challenged election, there were approximately 660 members in good standing of Local 3489. The Court of Appeals found that 96.5% of these members were ineligible to hold office, because of failure to satisfy the meeting-attendance rule.4 Of the 23 eligible members, nine were *308incumbent union officers. The Secretary argues, and the Court of Appeals held, that the failure of 96.5% of the local members to satisfy the meeting-attendance requirement, and the rule’s effect of requiring potential insurgent candidates to plan their candidacies as early as 18 months in advance of the election when the reasons for their opposition might not have yet emerged,5 established that the requirement has a substantial antidemocratic effect on local union elections. Petitioners argue that the rule is reasonable because it serves valid union purposes, imposes no very burdensome obligation on the members, and has not proved to be a device that entrenches a particular clique of incumbent officers in the local.
II
The opinions in three cases decided in 1968 have identified the considerations pertinent to the determination whether tlie attendance rule violates §401 (e). Wirtz v. Hotel Employees, 391 U. S. 492; Wirtz v. Bottle Blowers Assn., 389 U. S. 463; Wirtz v. Laborers’ Union, 389 U. S. 477.
The LMRDA does not render unions powerless to restrict candidacies for union office. The injunction in § 401 (e) *309that “every member in good standing shall be eligible to be a candidate and to hold office” is made expressly “subject to . . . reasonable qualifications uniformly imposed.” But “Congress plainly did not intend that the authorization . . . of ‘reasonable qualifications . . .’ should be given a broad reach. The contrary is implicit in the legislative history of the section and in its wording . . . .” Wirtz v. Hotel Employees, supra, at 499. The basic objective of Title IV of the LMRDA is to guarantee “free and democratic” union elections modeled on “political elections in this country” where “the assumption is that voters will exercise common sense and judgment in casting their ballots.” 391 U. S., at 504. Thus, Title IV is not designed merely to protect the right of a union member to run for a particular office in a particular election. “Congress emphatically asserted a vital public interest in assuring free and democratic union elections that transcends the narrower interest of the complaining union member.” Wirtz v. Bottle Blowers Assn., supra, at 475; Wirtz v. Laborers’ Union, supra, at 483. The goal was to “protect the rights of rank-and-file members to participate fully in the operation of their union through processes of democratic self-government, and, through the election process, to keep the union leadership responsive to the membership.” Wirtz v. Hotel Employees, supra, at 497.
Whether a particular qualification is “reasonable” within the meaning of § 401 (e) must therefore “be measured in terms of its consistency with the Act’s command to unions to conduct ‘free and democratic’ union elections.” 391 U. S., at 499. Congress was not concerned only with corrupt union leadership. Congress chose the goal of “free and democratic” union elections as a preventive measure “to curb the possibility of abuse by benevolent as well as malevolent entrenched leadership.” Id., at 503. Hotel Employees expressly held that that check was seriously impaired by candidacy qualifications which substantially deplete the ranks of those who might run in *310opposition to incumbents, and therefore held invalid the candidacy limitation there involved that restricted candidacies for certain positions to members who had previously held union office. “Plainly, given the objective of Title IY, a candidacy limitation which renders 93% of union members ineligible for office can hardly be a 'reasonable qualification.’ ” Id., at 502.
Ill
Applying these principles to this case, we conclude that here, too, the antidemocratic effects of the. meeting-attendance rule outweigh the interests urged in its support. Like the bylaw in Hotel Employees, an attendance requirement that results in the exclusion of 96.5% of the members from candidacy for union office hardly seems to- be a “reasonable qualification” consistent with the goal of free and democratic elections. A requirement having that result obviously severely restricts the free choice of the membership in selecting its leaders.
Petitioners argue, however, that the bylaw held violative of § 401 (e) in Hotel Employees differs significantly from the attendance rule here. Under the Hotel Employees bylaw no member could assure by his own efforts that he would be eligible for union office, since others controlled the criterion for eligibility. Here, on the other hand, • a member can assure himself of eligibility for candidacy by attending some 18 brief meetings over a three-year period. In other words, the union would have its rule treated not as excluding a category of member from eligibility, but simply as mandating a procedure to be followed by any member who wishes to be a candidate.
Even examined from this perspective, however, the rule has a restrictive effect on union democracy.'6 In the absence *311of a permanent “opposition party” within the union, opposition to the incumbent leadership is likely to emerge in response to particular issues at different times, and member interest in changing union leadership is therefore likely to be at its highest only shortly before elections.7 Thus it is probable that to require that a member decide upon a potential candidacy at least 18 months in advance of an election when no issues exist to prompt that decision may not foster but discourage candidacies and to that extent impair the general membership’s freedom to oust incumbents in favor of new leadership.
Nor are we persuaded by petitioners’ argument that the Secretary has failed to show an antidemocratic effect because he has not shown that the incumbent leaders of the union became “entrenched” in their offices as a consequence of the operation of the attendance rule. The reasons for leaderships becoming entrenched are difficult to isolate. The election of the same officers year after year may be a signal that antidemocratic election rules have prevented an effective challenge to the regime, or might well signal only that the members are satisfied with their stewardship; if elections are uncontested, opposition factions may have been denied access to the ballot, or competing interests may have compromised differences before the election to maintain a front of unity. Conversely, turnover in offices may result from an open political process, or from a competition limited to candidates who offer no real opposition to an entrenched establishment. But Congress did not saddle the courts with the duty to search out and remove improperly entrenched union leaderships Bather, Congress chose to guarantee union democracy *312by regulating not the results of a union’s electoral procedure but the procedure itself. Congress decided that if the elections are “free and democratic,” the members themselves are able to correct abuse of power by entrenched leadership. Procedures that unduly restrict free choice among candidates are forbidden without regard to their success or failure in maintaining corrupt leadership.
Petitioners next argue that the rule is reasonable within § 401 (e) because it encourages attendance at -union meetings, and assures more qualified officers by limiting election to those who have demonstrated an interest in union affairs, and are familiar with union problems. But the rule has plainly not served these goals. It has obviously done little to encourage attendance at meetings, which continue to attract only a handful of members.8 Even as to the more limited goal of encouraging the attendance of potential dissident candidates, very few members, as we have said, are likely to see themselves as such sufficiently far in advance of the election to be spurred to attendance by the rule.
As for assuring the election of knowledgeable and dedicated leaders, the election provisions of the LMRDA express a congressional determination that the best means to this end is to leave the choice of leaders to the membership in open democratic elections, unfettered by arbitrary exclusions. Pursuing this goal by excluding the bulk of the membership from eligibility for office, and thus limiting the possibility of dissident candidacies, runs directly counter to the basic premise of the statute. We therefore conclude that Congress, in guaranteeing every union member the opportunity to hold office, subject only to “reasonable qualifications,” *313disabled unions from establishing eligibility qualifications as sharply restrictive of the openness of the union political process as is petitioners’ attendance rule.
IY
Finally, petitioners argue that the absence of a precise statement of what the Secretary of Labor and the courts will regard as reasonable prevents the drafting of a meeting-attendance rule with any assurance that it will be valid under §401 (e). The Secretary, to whom Congress has assigned a special role in the administration of the Act, see Calhoon v. Harvey, 379 U. S. 134, 140 (1964); Dunlop v. Bachowski, 421 U. S. 560 (1975), has announced the following view:
“Experience has demonstrated that it is not feasible to establish arbitrary guidelines for judging the reasonableness of [a meeting-attendance eligibility requirement]. Its reasonableness must be gauged in the light of all the circumstances of the particular case, including not only the frequency of meetings, the number of meetings which must be attended and the period of time over which the requirement extends, but also such factors as the nature, availability and extent of excuse provisions, whether all or most members have the opportunity to attend meetings, and the impact of the rule, i. e., the number or percentage of members who would be rendered ineligible by its application.” 29 CFR §452.38 (a) (1976).
Obviously, this standard leads to more uncertainty than would a less flexible rule. But in using the word “reasonable,” Congress clearly contemplated exactly such a flexible result. Moreover, on the facts of this case and in light of Hotel Employees, petitioners’ contention that they had no way of knowing that a rule disqualifying over 90% of a local’s *314members from office would be regarded as unreasonable in the absence of substantial justification is unpersuasive.9
Affirmed.
Constitution of International Union, United Steelworkers of America, Art. VII, §9 (c) (1968).
This section provides, in pertinent part:
“(e) In any election required by this section which is to be held by secret ballot a reasonable opportunity shall be given for the nomination of candidates and every member in good standing shall be eligible to be a candidate and to hold office (subject to section 504 and to reasonable qualifications uniformly imposed) and shall have the right to vote for or otherwise support the candidate or candidates of his choice, without being subject to penalty, discipline, or improper interference or reprisal of any kind by such organization or any member thereof. . . . The election shall be conducted in accordance with the constitution and bylaws of such organization insofar as they are not inconsistent with the provisions of this title.”
The Steelworkers’ attendance requirement was held not to violate §401 (e) in Brennan v. Steelworkers, 489 F. 2d 884 (CA6 1973). Similar meeting-attendance requirements of other unions were found unreasonable in Usery v. Transit Union, 545 F. 2d 1300 (CA1 1976); Brennan v. Teamsters, 161 U. S. App. D. C. 173, 494 F. 2d 1092, 1099-1100 (1974); Wirtz v. Bottle Blowers Assn., 405 F. 2d 176 (CA3 1968).
Petitioners challenge this figure in this Court, but we cannot find it clearly erroneous. It is stipulated that of the approximately 660 members of the local, only 22 had attended enough meetings to qualify, and one additional member was found eligible by adding his excused *308absences to the meetings he attended. Petitioners now contend that other members may also have been eligible because of excused absences. In view of the admitted facts that the average attendance at meetings was
only 47, and that the meetings were held in split day and evening sessions so that workers on any shift could attend, it seems unlikely that a significant number of workers could qualify by this method. In any event, petitioners introduced no evidence to suggest that members other than the above 23 were eligible, and the District Court, in its unpublished opinion, apparently accepted the Secretary’s assertion that “in excess of 90%” of the local’s membership was disqualified. In these circumstances, we cannot speculate that the findings of the courts below may have been materially inaccurate.
Regular meetings were held on a monthly basis. Thus, in order to attend half of the meetings in a three-year period, a previously inactive member desiring to run for office would have to begin attending 18 months before the election.
Petitioners argue that attendance at 18 relatively short meetings over three years is no very onerous burden on a union member. But this argument misconceives the evil at which the statute aims. We must *311judge the eligibEity rule not by the burden it imposes on the individual candidate but by its effect on free and democratic processes of union government. Wirtz v. Hotel Employees, 391 U. S., at 499.
The Secretary suggests that in most unions there is no such organized opposition and that the pattern described in the text is indeed typical.
Attendance at Local 3489’s meetings averages 47 out of approximately 660 members. There is no indication in the record that this total represents a significant increase over attendance before the institution of the challenged rule.
Also unpersuasive is the argument that a union cannot know in advance how many of its members will be disqualified by a meeting-attendance rule. While the precise number may not be predictable, petitioners must have had some awareness of the general attendance rate at union meetings, and if Local 3489’s attendance rate is at all typical (and there is no contention that it is not), it should have been fairly obvious that a rule disqualifying all who had not maintained 50% attendance for three years, admittedly one of the most stringent such rules among labor unions, would have a significant antidemocratic impact.