Plaintiff, Westmac, Inc., has sued the defendants charging antitrust violations. The focus of this appeal concerns defendants’ opposition to plaintiff’s effort to obtain special tax benefit bond financing of a grain elevator facility in Clinton County, Michigan.1 Plaintiff appeals from a grant of summary judgment to defendants based on a claimed exemption from plaintiff’s antitrust claim known as the Noerr-Pennington doctrine. Plaintiff charged defendants with pursuing and conducting lobbying and litigation activities for the express purpose of forcing plaintiff to join an anticompetitive price maintenance conspiracy or, if that failed, to damage plaintiff economically by reducing or destroying its ability to compete. The district court held no genuine issue of material fact existed respecting whether defendants’ lobbying and litigation activities were “a genuine attempt to influence official decision making” protected by the Noerr-Pennington doctrine. We affirm.
I.
In 1974 the state legislature of Michigan enacted the Economic Development Corporations Act. Mich.Comp.Laws Ann. § 125.-1601-125.1636. The statute permits munic*315ipalities to form local Economic Development Corporations (EDCs) for the purpose of issuing revenue bonds. The proceeds are used for the construction of privately owned and operated businesses. In February 1981 Westmac approached the Clinton County Economic Development Corporation in order to obtain EDC bonding to assist in the financing of construction of a high speed grain elevator and railroad loading facility in that county. Westmac obtained initial approval of the project by the Clinton County EDC on February 26, 1981.
On April 3, 1981, defendant Lon Smith wrote other grain elevator operators in the area and urged them to communicate their concerns about the method of financing the new grain terminal to the Clinton County officials and to attend and voice their concerns at public hearings. On May 20,1981, the Mid-Michigan Farm and Grain Association was established for the stated purpose of promoting the economic welfare and stability of the agricultural industries of Central Michigan. The Clinton County EDC gave final approval of Westmae’s project on July 28, 1981. Westmac proceeded to arrange for issuance of the tax benefit bonds.
On August 5, 1981, Mid-Michigan filed suit against the Clinton County EDC in the Clinton County Circuit Court, challenging the constitutionality of the EDC Act. Westmac intervened in that suit as a party defendant. The court upheld the constitutionality of the statute. Mid-Michigan Farm & Grain Association, Inc. v. Henning, No. 81-3038-AN (Clinton Co.Cir.Ct. Dec. 10, 1981). The Michigan Court of Appeals affirmed. Mid-Michigan Farm & Grain Association, Inc. v. Henning, 127 Mich.App. 735, 339 N.W.2d 243 (1983). Plaintiff filed its antitrust complaint in the district court on December 30, 1981.
II.
Under the Noerr-Pennington doctrine, genuine attempts to influence passage or enforcement of laws are immune from antitrust scrutiny, regardless of the anticompetitive purpose behind such attempts. United Mine Workers v. Pennington, 381 U.S. 657, 669-71, 85 S.Ct. 1585, 1592-94,14 L.Ed.2d 626 (1965); Eastern Railroad Presidents Conference v. Noerr Motor Freight, Inc., 365 U.S. 127, 137-39, 81 S.Ct. 523, 529-30, 5 L.Ed.2d 464 (1961). As the Court stated in Pennington:
The legality of the conduct [in Noerr ] “was not at all affected by any anticompetitive purpose it may have had,” ... [365 U.S.] at 140 [81 S.Ct. at 531] — even though the “sole purpose in seeking to influence the passage and enforcement of laws was to destroy the truckers as competitors ...,” id., at 138 [81 S.Ct. at 530]. Nothing could be clearer from the Court’s opinion than that anticompetitive purpose did not illegalize the conduct there involved.
381 U.S. at 669, 85 S.Ct. at 1593. The right to petition, upon which the doctrine is based, see Noerr, 365 U.S. at 138, 81 S.Ct. at 530,2 extends to all departments of government, and therefore governs the access of citizens to courts and administrative agencies. California Motor Transport Co. v. Trucking Unlimited, 404 U.S. 508, 510, 92 S.Ct. 609, 611, 30 L.Ed.2d 642 (1972).
On the other hand, the Noerr-Pennington doctrine does not protect against improper attempts to influence the government or the courts that are a “mere sham to cover what is actually nothing more than an attempt to interfere directly with the business relationships of a competitor.” California Motor Transport, 404 U.S. at 511, 92 S.Ct. at 612 (quoting Noerr, 365 U.S. at 144, 81 S.Ct. at 533). In California Motor Transport the respondents sued petitioners on the grounds they conspired to monopolize trade and commerce in the trucking industry in violation of the anti*316trust laws. The respondents alleged petitioners conspired to institute repeated state and federal proceedings to defeat respondents’ applications to acquire operating rights or to transfer or register those rights. Id. 404 U.S. at 509, 92 S.Ct. at 611. The respondents’ sham theory in California Motor Transport was that petitioners on a number of occasions used their resources to harass and deter respondents in their access to administrative and judicial proceedings. The Court distinguished petitioners’ activity from the activity in Noerr. Id. at 508, 92 S.Ct. at 609. In Pennington the Court had stated that “Noerr shields from the Sherman Act a concerted effort to influence public officials regardless of intent or purpose.” 381 U.S. at 670, 85 S.Ct. at 1593. The California Transport Motor Court contrasted attempts to influence public officials from repeated efforts to block competitors from access to adjudicating tribunals, as allegedly occurred in California Motor Transport. Id. 404 U.S. at 511-12, 92 S.Ct. at 612. In this latter situation the Justices endorsed examining the purpose or intent of the alleged anticompetitive activities. Id.3 The Court reiterated that when the exercise of first amendment rights is an integral part of conduct that violates a valid statute or constitutes an abuse of process it is not immunized from regulation. Id. at 514-15, 92 S.Ct. at 613-14. The Court elaborated that “First Amendment rights may not be used as the means or the pretext for achieving ‘substantive evils.’ ” Id. at 515, 92 S.Ct. at 614 (citation omitted).
Subsequent cases have attempted to clarify the scope of the sham exception to the Noerr-Pennington doctrine. In Winter-land Concessions Co. v. Trela, 735 F.2d 257, 263 (7th Cir.1984), the plaintiff alleged that defendant employed various tactics to deny plaintiff a judicial determination or definition of defendant’s property rights. The court, in attempting to define the parameters of the sham exception, noted that litigation may be used for improper purposes, such as suppressing competition. The panel defined sham litigation as litigation filed by an individual solely to harass and not to win a favorable judgment. Id. (quoting Grip-Pak, Inc. v. Illinois Tool Works, Inc., 694 F.2d 466, 472 (7th Cir.1982), cert. denied, 461 U.S. 958, 103 S.Ct. 2430, 77 L.Ed.2d 1317 (1983)). The court carefully distinguished between an anti-competitive purpose, which the Noerr doctrine does protect, and the purpose to harm competitors “not by the result of the litigation, but by the simple fact of the institution of the litigation.” Id. at 264 (quoting Gainesville v. Florida Power & Light Co., 488 F.Supp. 1258, 1265-66 (S.D.Fla.1980)). Since plaintiff alleged defendant’s purpose was to eliminate plaintiff and not to obtain a judgment, the court reversed the district court’s dismissal of plaintiff’s antitrust claim.
In Omni Resource Development Corp. v. Conoco, Inc., 739 F.2d 1412 (9th Cir. 1984), the defendant successfully obtained a preliminary injunction against plaintiff in a state trespass suit. Id. at 1413. The plaintiff alleged that defendant used false and fraudulent affidavits in the suit in a scheme to restrain trade. The court assumed this activity was at least tortious under state law, but nevertheless determined it to be protected under the first amendment unless “undertaken solely to interfere with free competition and without the legitimate expectation that such efforts will in fact induce lawful government action.” Id. at 1413 (citing Noerr, 365 U.S. at 144, 81 S.Ct. at 533). The Ninth Circuit further noted that when the antitrust activity concerns only a single baseless suit,4 *317rather than a pattern of repeated filings, the sham exception does not apply unless the baseless suit has other characteristics of grave abuse. Id. at 1414.5 The court affirmed the trial court’s judgment on the pleadings in favor of defendants.6 See also Cleveland v. Cleveland Electric Illuminating, 734 F.2d 1157 (6th Cir.), cert. denied, — U.S. -, 105 S.Ct. 253, 83 L.Ed.2d 190 (1984).
In the recent case of Razorback Ready Mix Concrete Co. v. Weaver, 761 F.2d 484 (8th Cir.1985), the court reversed the district court’s order denying defendant’s motion to grant summary judgment because the panel found that the Noerr-Pennington doctrine protected defendant’s conduct. Defendants had opposed a bond issue, the proceeds from which plaintiff sought to pay its corporate debt. The sale of the plaintiff’s business was contingent on the bond issue. Id. at 486. Defendants unsuccessfully lobbied against the bond issue with local officials. They subsequently filed a suit and later perfected an appeal in state court challenging the propriety of the bond issue. Id. As an alleged result of defendants’ actions, the bonds were not issued and plaintiff went into bankruptcy. Id. The court held the sham exception was inapplicable as a matter of law, concluding that the key to the sham exception is “an improper interference with governmental processes.” Id. at 487. It suggested the “improper interference” to which it referred is “illegal reprehensible practices such as penury, fraud, conspiracy with or bribery of governmental decision makers, or misrepresentation, or is so clearly baseless as to amount to an abuse of process.”7 Id. (quoting Chest Hill Co. v. Gluttman, 1981-2 Trade Cas. (CCH) ¶ 64,417 (S.D.Ohio May 29, 1981)); see also Energy Conservation, Inc. v. Heliodyne, Inc., 698 F.2d 386, 388 (9th Cir.1983) (“[T]he application of the antitrust laws need not be waived when the bringing of a suit is solely an effort to interfere directly with a competitor.”) (emphasis added); Alexander v. National Farmers Organization, 687 F.2d 1173, 1195 (8th Cir.1982) (“The sham exception generally involves governmental contacts which are not a genuine attempt to influence official decision making, but instead are merely an attempt to interfere directly with the business relationships of a competitor.”) (emphasis added), cert. denied, 461 U.S. 937, 103 S.Ct. 2108, 77 L.Ed.2d 313 (1983); Associated Container Transp. (Australia) Ltd. v. United States, 705 F.2d 53, 58 (2d Cir.1983) (“The Noerr-Pennington doctrine ... does not ... shield those who attempt to abuse the governmental process for the purpose of injuring a competitor.”).
III.
We find persuasive the reasoning in Razorback that states the sham exception does not apply merely because a party files a suit with the principle purpose of harming his competitor. The first amendment, as expressed in the Noerr-Pennington doctrine, protects even strongly expressed anticompetitive sentiments. At the same time, we are cognizant that the Supreme Court ruled in California Motor Transport that intent is relevant when a party allegedly filed a suit without concern for obtaining a favorable judgment, but only directly to harm a competitor. As the Fifth Circuit recently stated:
*318The problem stems in part from the fact that determining whether the petitioning conduct was a sham often involves questions of motive or subjective intent. For example, the conduct protected by the Court in Noerr was an advertising campaign by the railroads directed against the trucking industry and intended to persuade the state legislature to enact laws detrimental to truckers. If the ad campaign had been instituted for the purpose of injuring the trucking industry directly, rather than in an effort to persuade the legislature to take action, the activity would have been a sham. Similarly, if a competitor instituted an action against his rival before a regulatory agency in order to force him to defend against the action rather than in hopes of a favorable agency ruling, the activity would not be bona fide petitioning conduct. Developing criteria to separate legitimate efforts from others is not simple. See generally P. Areeda, Antitrust Law 11203 (1982 Supp.).
Greenwood Utilities Commission v. Mississippi Power Co., 751 F.2d 1484, 1498 n. 9 (5th Cir.1985).
We also agree with the rationale of Razorback that the sham exception is a “narrow one” and “is applicable when the activity in question corrupts governmental processes to such an extent that it constitutes access barring conduct of the sort described in California Motor.” 761 F.2d at 487 (citing Woods Exploration & Producing Company v. Aluminum Company of America, 438 F.2d 1286, 1296-98 (5th Cir. 1971), cert. denied, 404 U.S. 1047, 92 S.Ct. 701, 30 L.Ed.2d 736 (1972)). We further agree with that court’s reasoning that “the key to the ‘sham exception’ is an improper interference with governmental process.” Id. at 487.8
Determining whether a party who filed suit was indifferent to obtaining a favorable judgment may often be a difficult question of fact. Accord Grip-Pak, 694 F.2d at 472. We hold that when a lawsuit raises a legal issue of genuine substance, it raises a rebuttable presumption that it is a serious attempt to obtain a judgment on the merits instead of a mere sham or harassment. The first amendment interests concerned and the case law discussed earlier support placing the evidentiary burden on the antitrust plaintiff to prove that the action of the defendant comes within the sham exception to NoerrPennington in this kind of case.
IV.
Application of these principles to the facts of this case suggest that the defendants’ activities in pursuing the lawsuit do not fit within the sham exception. The district court emphasized that the Michigan courts did not treat defendants’ suit as without merit or a mere sham. The state court referred to the suit as a “fundamental and well articulated challenge to the constitutional validity of the Economic Development Corporations Act.” On these essentially undisputed facts we find defendants’ state suit to have raised a substantial issue of state law. We may therefore presume that defendants filed the suit as a genuine attempt to obtain a judgment on the merits, even if they also intended to prevent plaintiff from obtaining a tax and economic benefit as a potential competitor.
Plaintiff has not rebutted this presumption. Plaintiff principally bases its argument that the sham exception applies on a memorandum written by one defendant that states in part: “If this [lobbying activity] doesn’t succeed, start a lawsuit-bonds won’t sell.” The memorandum to this defendant’s lawyer also pointed out that a “requirement” of the EDC was to serve the “public purpose” and that this needed to be “our focus.” It emphasized “we need local support,” and that the act was “unconstitutional-no equal protection of law,” and it *319directed that the attorney “start legal action when county commissioners give approval.”
Although this statement may support plaintiffs theory of defendants’ anticompetitive animus, it does not alter the protected nature of their litigation activities. This memo does memorialize a series of efforts to prevent plaintiff from selling the bonds. The memo suggests that if these efforts did not succeed, then the defendants should institute a lawsuit challenging the constitutionality of the bonds. But we agree with the district court’s view that the memo does not raise a sufficient fact issue regarding the intent of defendants to preclude granting them summary judgment.9
The district court took full account of this court’s admonition in Taylor Drug Stores, Inc. v. Associated Dry Goods Corp., 560 F.2d 211, 213 (6th Cir.1977) (per curiam): “[S]ummary judgment is rarely an appropriate response to antitrust litigation, since such litigation so frequently turns upon disputed issues of fact.” It properly also noted, however, that summary judgment is available in proper circum-
stances in antitrust cases when there are no disputed material facts, or if the issue presented is clearly a question of law. Id; see also Razorback Ready Mix Concrete v. Weaver, 761 F.2d 484 (8th Cir.1985); Comet Mechanical Contractors, Inc. v. E.A. Cowen Construction, Inc., 609 F.2d 404, 405 (10th Cir.1980). Here the parties have pursued discovery and the facts are clear regarding the circumstances of the filing of the suit and that the state courts considered the suit to present substantial issues, even though defendants were not ultimately successful. This court has approved granting of summary judgment concerning antitrust claims under such circumstances. See Smith v. Northern Michigan Hospitals, Inc., 703 F.2d 942, 947-48 (6th Cir.1983).10
We find that granting of summary judgment in this case was not error. We assume that defendants’ purpose “was either to stop or delay sale of the EDC bonds or prevent the EDC financing” as asserted by plaintiff. But plaintiff concedes that the “Clinton County Circuit Court Judge did not treat the [defendants’] case as a ‘sham.’ ”11 Instead the state court viewed *320the case as raising an important legal question. The substance of the defendants’ state case raises a rebuttable presumption that their lawsuit was a genuine attempt to obtain a favorable judgment.12 Plaintiff does not allege facts that can rebut this presumption.
Accordingly, we AFFIRM the district court’s grant of summary judgment.
. By stipulation, plaintiff conceded that its "remaining and State law based claims" brought about no "economic damages" beyond the “inception of litigation by the defendant[s],” which is the subject matter of the appeal.
. The conduct in Noerr concerned an alleged conspiracy to monopolize and restrain trade in the long-distance freight business in violation of sections 1 and 2 of the Sherman Act. The truckers alleged that the railroads sought to achieve their illegal goals by conducting a publicity campaign against truckers designed to destroy them. 365 U.S. at 129, 81 S.Ct. at 525.
. The Court noted that although unethical conduct was insufficient to satisfy the sham exception in Noerr when the conspiracy concerned lobbying activities, it can be sufficient when the conspiracy concerns use of adjudicatory processes. 404 U.S. at 512, 92 S.Ct. at 612. The Court gave as an example of unethical conduct such activities as perjury, fraud, conspiracy, bribery, misrepresentations, a pattern of baseless, repetitive claims, or other kinds of abuse of process. Id. at 512-13, 92 S.Ct. at 612-13.
. Plaintiff urges this court to resolve the question whether the sham exception requires more than one baseless suit. See Cleveland v. Cleveland Electric Illuminating Co., 734 F.2d 1157, *3171162-63 (6th Cir.), cert. denied, — U.S. -, 105 S.Ct. 253, 83 L.Ed.2d 190 (1984). But in view of our agreement with the district court’s determination that defendant’s state suit was not baseless, the issue is not before the court.
. One example of grave abuse is litigation that is an integral part of a larger antitrust conspiracy. 739 F.2d at 1415.
. The court emphasized that the judgment resulting from defendant’s suit, not the mere filing of the suit, was the cause of plaintiffs harm. 739 F.2d at 1414.
. Some language in Razorback arguably suggests that a party’s motive in bringing a suit is never relevant. See 761 F.2d at 488 ("Defendants’ motive may have been selfish or altruistic or mixed; that is immaterial. Regardless of motive, defendants’ actions are clearly within the ambit of First Amendment protection....”). But see California Motor Transport, 404 U.S. at 511-12, 92 S.Ct. at 612.
. Razorback’s facts are in many ways analogous to those in this case. A group of competitors in Razorback opposed the bond issue for a competitor. When the county judge approved the bond issue, they challenged this action in court, alleging that the bond issue violated the Arkansas constitution. They lost in the trial court and appealed.
. It defies common sense to suggest defendants did not seek a favorable judgment. A favorable judgment declaring the state law unconstitutional would have prevented the sale of the bonds, which was defendants’ allegedly anticompetitive purpose. The record on appeal does not suggest that this is a case in which "... the stakes, discounted by the probability of winning, would be too low to repay the investment in litigation." Grip-Pak, 694 F.2d at 472 (Judge Posner discussing examples of when the stakes would suggest defendant’s purpose was not to obtain a favorable judgment).
Other circumstances indicate that the state court action was not a sham or in any way an abuse of the judicial process. Defendants promptly stipulated that plaintiff might intervene. There was also a further agreement providing that the Michigan court give expedited consideration to the defendants’ suit challenging the constitutionality of the Michigan law authorizing the EDC. These arrangements indicate that the defendants’ state suit was not an effort to defeat plaintiffs EDC petition by delay, harassment, or any kind of "reprehensible practice.”
. We do not consider the conversation between plaintiffs president and Bowles, a former member of the Mid-Michigan Farm and Grain Association, that upon certain conditions the latter "believed” or "felt" that he might get the group to drop its appeal and effect a settlement to be a material circumstance precluding a grant of summary judgment. In granting summary judgment the district court gave plaintiffs contentions the benefit of the doubt. It assumed an "attempt to influence official decision making” and "anti-competitive purpose” on the part of defendants, but it held this behavior to be protected and exempted from antitrust claims because defendants’ actions, particularly in bringing about the constitutional challenge in court, were not an "abuse of governmental processes,” nor "unlawful lobbying activities," nor "sham” litigation. The district court held that to come within the sham exception to the Noerr-Pennington doctrine, which protects the important first amendment right of petition, the legal action must be shown to be "baseless, initiated without probable cause, or tainted by fraud, perjury, bribery, or other practices constituting a corruption of the judicial process.”
. We acknowledge, however, plaintiffs contention that evidence which "supports” its sham theory was not before the state judge, but the contention was considered by the district court, which concluded: "[pjlaintiffs in the present *320case present no facts to support an inference that the defendants abused the judicial process____”
. The dissent implies that by creating the presumption in the present case we are immunizing from government regulation the challenged conduct, which concededly may have an anti-competitive effect. But we have not "immunized" defendants’ conduct in the present case because we have afforded the plaintiff an opportunity to demonstrate that defendants’ state court suit was something other than a serious challenge to the validity of the state law relied upon by plaintiff to obtain a special tax benefit. The dissent asserts that we should determine whether the defendant's action and motivation in bringing the state court challenge amounted to an “abuse of process.” See Grip-Pak, 694 F.2d at 471-72. We do not disagree that if plaintiff could establish that defendants’ actions constitute the tort of abuse of process, in the sense that defendants’ suit corrupted or improperly interferred with the judicial process, that the sham exception does apply. See Razorback, 761 F.2d at 487; Assoc. Container Transp., 705 F.2d at 59 (states that "abuses of the governmental process” such as “misrepresentations” or "a pattern of baseless repetitive claims may induce antitrust liability"). We merely are creating an evidentiary presumption to facilitate the applicability of the sham exception. We would also agree with the dissent's acknowlegement that defendants probably would admit that they filed their state court action with an intent to impede or damage plaintiff’s effort to construct a competing grain elevator aided by special statutory benefits, and that such intent is insufficient as a matter of law to take this action out of the protection of the Noerr-Pennington doctrine. See dissent at n. 4.