MR. CHIEF JUSTICE BURGER, concurring in the Court's opinion in Part I and in the judgment.

This case turns, or ought to, on the District Court's explicit conclusion, unchallenged here, that "[t]hese plaintiff cities are engaging in what is clearly a business activity; activity in which a profit is realized." There is nothing in Parker v. Brown, 317 U.S. 341 (1943), or its progeny, which suggests that a proprietary enterprise with the inherent capacity for economically disruptive anticompetitive effects should be exempt from the Sherman Act merely because it is organized under state law as a municipality. Parker was a case involving a suit against state officials who were administering a state program which had the conceded purpose of replacing competition in a segment of the agricultural market with a regime of governmental regulation. The instant lawsuit is entirely different. It arises because respondent took the perfectly natural step of answering a federal antitrust complaint — filed by competitors — with a counterclaim alleging serious violations of the Sherman Act.

There is nothing in this record to support any assumption other than that this is an ordinary dispute among competitors in the same market. It is true that petitioners are municipalities, but we should not ignore the reality that this is the only difference between the Cities and any other entrepreneur in the economic community. Indeed, the injuries alleged in petitioners' complaint read as a litany of economic woes suffered by a business which has been unfairly treated by a competitor:

"As a direct and proximate result of the unlawful conduct hereinabove alleged, plaintiffs have: (1) been prevented from and continue to be prevented from profitably expanding their businesses; (2) lost and continue to lose the profits which would have resulted from the operation of an expanded, more efficient and lower cost business; (3) been deprived of and continue to be deprived of economies in the financing and operation of their systems; (4) sustained and continue to sustain losses in the value of their businesses and properties; and (5) incurred and continue to incur excessive costs and expenses they otherwise would not have incurred." App. 14. (Emphasis added.)

It strikes me as somewhat remarkable to suggest that the same Congress which "meant to deal comprehensively and effectively with the evils resulting from contracts, combinations and conspiracies in restraint of trade," Atlantic Cleaner Dyers, Inc. v. United States, 286 U.S. 427, 435 (1932), would have allowed these petitioners to complain of such economic damage while baldly asserting that any similar harms they might unleash upon competitors or the economy are absolutely beyond the purview of federal law. To allow the defense asserted by the petitioners in this case would inject a wholly arbitrary variable into a "fundamental national economic policy," Carnation Co. v. Pacific Conference, 383 U.S. 213, 218 (1966), which strongly disfavors immunity from its scope. See United States v. Philadelphia Nat. Bank, 374 U.S. 321, 350-351 (1963); California v. FPC, 369 U.S. 482, 485 (1962).

As I indicated, concurring in Cantor v. Detroit Edison Co., 428 U.S. 579, 604 (1976), "in interpreting Parker, the Court has heretofore focused on the challenged activity, not upon the identity of the parties to the suit." Such an approach is surely logical in light of the fact that the Congress which passed the Sherman Act very likely never considered the kinds of problems generated by Parker and the cases which have arisen in its wake. E.g., Bates v. State Bar of Arizona, 433 U.S. 350 (1977); Cantor, supra; Goldfarb v. Virginia State Bar, 421 U.S. 773 (1975); see Slater, Antitrust and Government Action: A Formula for Narrowing Parker v. Brown, 69 Nw. U. L. Rev. 71, 84 (1974). It is even more dubious to assume that the Congress specifically focused its attention on the possible liability of a utility operated by a subdivision of a State. Not only were the States generally considered free to regulate commerce within their own borders, see, e.g., United States v. E.C. Knight Co., 156 U.S. 1 (1895); Kidd v. Pearson, 128 U.S. 1 (1888), but manufacturing enterprises, in and of themselves, were not taken to be interstate commerce. Id., at 20.

By the time Parker was decided, however, this narrow view of "interstate commerce" had broadened via the "affection doctrine" to include intrastate events which had a sufficient effect on interstate commerce. See NLRB v. Fainblatt, 306 U.S. 601, 605, and n. 1 (1939); cf. Hospital Building Co. v. Rex Hospital Trustees, 425 U.S. 738, 743 (1976). Given this development, and the Court's interpretation of "person" or "persons" in the Sherman Act to include States and municipalities, ante, at 394-397, along with the trend of allowing the reach of the Sherman Act to expand with broadening conceptions of congressional power under the Commerce Clause, see Rex Hospital Trustees, supra, at 743 n. 2, one might reasonably wonder how the Court reached its result in Parker.

The holding in Parker is perfectly understandable, though, in light of the historical period in which the case was decided. The Court had then but recently emerged from the era of substantive due process, and was undoubtedly not eager to commence a new round of invalidating state regulatory laws on federal principles. See Verkuil, State Action, Due Process and Antitrust: Reflections on Parker v. Brown, 75 Colum. L. Rev. 328, 331-334 (1975). Responding to this concern, the Parker Court's interpretation of legislative intent reflects a "polic[y] of signal importance in our national traditions and governmental structure of federalism." Ante, at 400.

"In a dual system of government in which, under the Constitution, the states are sovereign, save only as Congress may constitutionally subtract from their authority, an unexpressed purpose to nullify a state's control over its officers and agents is not lightly to be attributed to Congress." Parker, 317 U.S., at 351.

The Parker decision was thus firmly grounded on principles of federalism, the ambit of its inquiry into congressional purpose being defined by the Court's view of the requirements of "a dual system of government."

This mode of analysis is as sound today as it was then, and I am surprised that neither the plurality opinion nor the dissents focus their attention on this aspect of Parker. Indeed, it is even more puzzling that so much judicial energy is expended here on deciding a question not presented by the parties or by the facts of this case: that is, to what extent the Sherman Act impinges generally upon the monopoly powers of state and local governments. As I suggested at the outset, the issue here is whether the Sherman Act reaches the proprietary enterprises of municipalities.

The answer to the question presented ought not to be so difficult. When Parker was decided there was certainly no question that a State's operation of a common carrier, even without profit and as a "public function," would be subject to federal regulation under the Commerce Clause. United States v. California, 297 U.S. 175, 183-186 (1936) ("[W]e think it unimportant to say whether the state conducts its railroad in its 'sovereign' or in its 'private' capacity." Id., at 183); see Parden v. Terminal R. Co., 377 U.S. 184, 189-193 (1964); California v. Taylor, 353 U.S. 553, 568 (1957). Likewise, it had been held in Ohio v. Helvering, 292 U.S. 360 (1934), that a State, upon engaging in business, became subject to a federal statute imposing a tax on those dealing in intoxicating liquors, although States were not specifically mentioned in the statute. In short, the Court had already recognized, for purposes of federalism, the difference between a State's entrepreneurial personality and a sovereign's decision — as in Parker — to replace competition with regulation.

I see nothing in the last 35 years to question this conclusion. In fact, the Court's recent decision in National League of Cities v. Usery, 426 U.S. 833 (1976), which rekindled a commitment to tempering the Commerce Clause power with the limits imposed by our structure of government, employs language strikingly similar to the words of Mr. Chief Justice Stone in Parker:

"It is one thing to recognize the authority of Congress to enact laws regulating individual businesses necessarily subject to the dual sovereignty of the government of the Nation and of the State in which they reside. It is quite another to uphold a similar exercise of congressional authority directed, not to private citizens, but to States as States. We have repeatedly recognized that there are attributes of sovereignty attaching to every state government which may not be impaired by Congress, not because Congress may lack an affirmative grant of legislative authority to reach the matter, but because the Constitution prohibits it from exercising the authority in that manner." 426 U.S., at 845.

The National League of Cities opinion focused its delineation of the "attributes of sovereignty" alluded to above on a determination as to whether the State's interest involved "'functions essential to separate and independent existence.'" Ibid., quoting Coyle v. Oklahoma, 221 U.S. 559, 580 (1911). It should be evident, I would think, that the running of a business enterprise is not an integral operation in the area of traditional government functions. See Alfred Dunhill of London, Inc. v. Cuba, 425 U.S. 682, 695-696 (1976); Bank of United States v. Planters' Bank of Georgia, 9 Wheat. 904, 907 (1824). Indeed, the reaffirmance of the holding in United States v. California, supra, by National League of Cities, supra, at 854 n. 18, strongly supports this understanding. Even if this proposition were not generally true, the particular undertaking at issue here — the supplying of electric service — has not traditionally been the prerogative of the State. Jackson v. Metropolitan Edison Co., 419 U.S. 345, 352-353 (1974).

Following the path outlined above should lead us to a logical destination: Petitioners should be treated, for purposes of applying the federal antitrust laws, in essentially the same manner as respondent. This is not to say, of course, that the conduct in which petitioners allegedly engaged is automatically subject to condemnation under the Sherman Act. As the Court recognized in Cantor v. Detroit Edison Co., 428 U.S., at 592-598, state-regulated utilities pose special analytical problems under Parker. It may very well be, for example, that a State, acting as sovereign, has imposed a system of governmental control in order "to avoid the consequences of unrestrained competition." Cantor, supra, at 595. This is precisely what occurred in Parker, and there is no question that a utility's action taken pursuant to the command of such an "act of government," Parker, 317 U.S., at 352, would not be prohibited by the Sherman Act.

I agree with the plurality, then, that "[t]he threshold inquiry in determining if an anticompetitive activity is state action of the type the Sherman Act was not meant to proscribe is whether the activity is required by the State acting as sovereign." Goldfarb, 421 U.S., at 790. (Emphasis added.) But this is only the first, not the final step of the inquiry, for Cantor recognized that "all economic regulation does not necessarily suppress competition." 428 U.S., at 595. "There is no logical inconsistency between requiring such a firm to meet regulatory criteria insofar as it is exercising its natural monopoly powers and also to comply with antitrust standards to the extent that it engages in business activity in competitive areas of the economy." Id., at 596.

I would therefore remand, directing the District Court to take an additional step beyond merely determining — as the plurality would — that any area of conflict between the State's regulatory policies and the federal antitrust laws was the result of a "state policy to displace competition with regulation or monopoly public service." Ante, at 413. This supplemental inquiry would consist of determining whether the implied exemption from federal law "was necessary in order to make the regulatory Act work, 'and even then only to the minimum extent necessary.'" 428 U.S., at 597.

MR. JUSTICE STEWART, with whom MR. JUSTICE WHITE, MR. JUSTICE BLACKMUN,[fn*] and MR. JUSTICE REHNQUIST join, dissenting. [fn*]426MR. JUSTICE BLACKMUN joins all but Part II-B of this opinion.

In Parker v. Brown, 317 U.S. 341, a California statute restricted competition among raisin growers in order to keep the price of raisins artificially high. The Court found that California's program did not violate the antitrust laws but was "an act of government which the Sherman Act did not undertake to prohibit." Id., at 352. Parker v. Brown thus made clear that "where a restraint upon trade or monopolization is the result of valid governmental action, as opposed to private action, no violation of the [Sherman] Act can be made out." Eastern Railroad Presidents Conf. v. Noerr Motor Freight, Inc., 365 U.S. 127, 136.

The principle of Parker v. Brown controls this case. The petitioners are governmental bodies, not private persons, and their actions are "act[s] of government" which Parker v. Brown held are not subject to the Sherman Act. But instead of applying the Parker doctrine, the Court today imposes new and unjustifiable limits upon it. According to the plurality, governmental action will henceforth be immune from the antitrust laws only when "authorized or directed" by the State "pursuant to state policy to displace competition with regulation or monopoly public service." Ante, at 414, 413. Such a "direction" from the State apparently will exist only when it can be shown "'from the authority given a governmental entity to operate in a particular area, that the legislature contemplated the kind of action complained of.'" Ante, at 415. By this exclusive focus on a legislative mandate the plurality has effectively limited the governmental action immunity of the Parker case to the acts of a state legislature. This is a sharp and I think unjustifiable departure from our prior cases.

THE CHIEF JUSTICE adopts a different approach, at once broader and narrower than the plurality's. In his view, municipalities are subject to antitrust liability when they engage in "proprietary enterprises," ante, at 422, but apparently retain their antitrust immunity for other types of activity. But a city engaged in proprietary activity is to be treated as if it were a private corporation: that is, it is immune from the antitrust laws only if it shows not merely that its action was "'required by the State acting as sovereign'" but also that such immunity is "'necessary in order to make the [State's] regulatory Act work.'" Ante, at 425, 426. THE CHIEF JUSTICE'S approach seems to me just as mistaken as the plurality's.

I

The fundamental error in the opinions of the plurality and THE CHIEF JUSTICE is their failure to recognize the difference between private activities authorized or regulated by government on the one hand, and the actions of government itself on the other.

A

In determining whether the actions of a political subdivision of a State as well as those of a state legislature are immune from the Sherman Act, we must interpret the provisions of the Act "in the light of its legislative history and of the particular evils at which the legislation was aimed." Apex Hosiery Co. v. Leader, 310 U.S. 469, 489. Those "particular evils" did not include acts of governmental bodies. Rather, Congress was concerned with attacking concentrations of private economic power unresponsive to public needs, such as "these great trusts, these great corporations, these large moneyed institutions." 21 Cong. Rec. 2562 (1890).

Recognizing this congressional intent, the Court in Parker v. Brown held that the antitrust laws apply to private and not governmental action. The program there at issue was in fact established by California's legislature, and not by one of its political subdivisions. But the Court nowhere held that the actions of municipal governments should not equally be immune from the antitrust laws. On the contrary, it expressly equated "the state or its municipality." 317 U.S., at 351. The Parker opinion repeatedly and carefully emphasized that California's program was not the action of "private persons, individual or corporate." Id., at 350 The distinction established in Parker v. Brown was not one between actions of a state legislature and those of other governmental units. Rather, the Court drew the line between private action and governmental action.

There can be no doubt on which side of this line the petitioners' actions fall. "Municipal corporations are instrumentalities of the State for the convenient administration of government within their limits." Louisiana ex rel. Folsom v. Mayor of New Orleans, 109 U.S. 285, 287; cf. Reynolds v. Sims, 377 U.S. 533, 575. They have only such powers as are delegated them by the State of which they are a subdivision, and when they act they exercise the State's sovereign power. Avery v. Midland County, 390 U.S. 474, 480; Breard v. Alexandria, 341 U.S. 622, 640. City governments are not unaccountable to the public but are subject to direct popular control through their own electorates and through the state legislature. They are thus a far cry from the private accumulations of wealth that the Sherman Act was intended to regulate.

B

The plurality today advances two reasons for holding nonetheless that the Parker doctrine is inapplicable to municipal governments. First, the plurality notes that municipalities cannot claim the State's sovereign immunity under the Eleventh Amendment. Ante, at 412. But this is hardly relevant to the question of whether they are within the reach of the Sherman Act. That question must be answered by reference to congressional intent, and not constitutional principles that apply in entirely different situations. And if constitutional analogies are to be looked to, a decision much more directly related to this case than those under the Eleventh Amendment is National League of Cities v. Usery, 426 U.S. 833. That case, like this one, involved an exercise of Congress' power under the Commerce Clause, and held that States and their political subdivisions must be given equal deference. Id., at 855-856, n. 20. The plurality does not advance any basis for its disregard of National League of Cities and its reliance instead on the basically irrelevant body of law under the Eleventh Amendment.

Secondly, the plurality relies on Goldfarb v. Virginia State Bar, 421 U.S. 773. The Goldfarb case, however, did not overrule Parker v. Brown but rather applied it. Goldfarb concerned a scheme regulating economic competition among private parties, namely, lawyers. The Court held that this "private anticompetitive activity," 421 U.S., at 792, could not be sheltered under the umbrella of the Parker doctrine unless it was compelled by the State. Since the bar association and State Bar could show no more than that their minimum-fee schedule "complemented" actions of the State, id., at 791, the scheme was not immune from the antitrust laws. Cf. Schwegmann Bros. v. Calvert Distillers Corp., 341 U.S. 384.

Unlike Goldfarb, this case does not involve any anticompetitive activity by private persons. As noted in Bates v. State Bar of Arizona, 433 U.S. 350, 361, actions of governmental bodies themselves present "an entirely different case" falling squarely within the rule of Parker v. Brown. Although the State Bar in Goldfarb was "a state agency for some limited purposes," 421 U.S., at 791, the price fixing it fostered was for the private benefit of its members and its actions were essentially those of a private professional group. Cf. Asheville Tobacco Board of Trade, Inc. v. FTC, 263 F.2d 502, 508-510 (CA4). Unlike a city, the Virginia State Bar surely is not "a political subdivision of the State."

By requiring that a city show a legislative mandate for its activity, the plurality today blurs, if indeed it does not erase, this logical distinction between private and governmental action. In Goldfarb and in Cantor v. Detroit Edison Co., 428 U.S. 579, the Court held that private action must be compelled by the state legislature in order to escape the reach of the Sherman Act. State compulsion is an appropriate requirement when private persons claim that their anticompetitive actions are not their own but the State's, since a State cannot immunize private anticompetitive conduct merely by permitting it. But it is senseless to require a showing of state compulsion when the State itself acts through one of its governmental subdivisions. See New Mexico v. American Petrofina, Inc., 501 F.2d 363, 369-370 (CA9).

C

The separate opinion of THE CHIEF JUSTICE does not rely on any distinctions between States and their political subdivisions. It purports to find a simpler reason for subjecting the petitioners to antitrust liability despite the fact that they are governmental bodies, namely, that Parker v. Brown does not protect "a State's entrepreneurial personality." Ante, at 422. But this distinction is no more substantial a basis for disregarding the governmental action immunity in this case than the reasons advanced by the plurality.

A State may choose to regulate private persons providing certain goods or services, or it may provide the goods and services itself. The State's regulatory body in the former case, or a state-owned utility in the latter, will necessarily make economic decisions. These decisions may be responsive to similar concerns, and they may have similar anticompetitive effects. Yet, according to THE CHIEF JUSTICE, the former type of governmental decision is immune from antitrust liability while the latter is not.

There is no basis for this distinction either in the Sherman Act itself or in our prior cases interpreting it. To the contrary, Parker v. Brown established that governmental actions are not regulated by the Sherman Act. See supra, at 428-430. And, as this Court has previously said:

"'Government is not partly public or partly private, depending upon the governmental pedigree of the type of a particular activity or the manner in which the Government conducts it.' Federal Crop Insurance Corp. v. Merrill, 332 U.S. 380, 383-384. On the other hand, it is hard to think of any governmental activity on the 'operational level,' our present concern, which is 'uniquely governmental,' in the sense that its kind has not at one time or another been, or could not conceivably be, privately performed." Indian Towing Co. v. United States, 350 U.S. 61, 67-68.

Nonetheless THE CHIEF JUSTICE would treat some governmental actions as governmental for purposes of the antitrust laws, and some as if they were not governmental at all.

Moreover, the scope of the immunity envisioned by THE CHIEF JUSTICE is virtually impossible to determine. The distinction between "proprietary" and "governmental" activities has aptly been described as a "quagmire." Id., at 65. The "distinctions [are] so finespun and capricious as to be almost incapable of being held in the mind for adequate formulation." Id., at 65-68. The separate opinion of THE CHIEF JUSTICE does nothing to make these distinctions any more substantial or understandable. Indeed, even a moment's consideration of the range of services provided today by governments shows how difficult it is to determine whether or not they are "proprietary." For example, if a city or State decides to provide water service to its citizens at cost on a monopoly basis, is its action to be characterized as "proprietary"? Whether it is "proprietary" or not, it is surely an act of government, as are the petitioners' actions in this case. Cf. Lowenstein v. Evans, 69 F. 908 (C.C.S.C.). But THE CHIEF JUSTICE, like the plurality, ignores what seems to me the controlling distinction in this case, that between private and governmental action.

II

The Court's decision in this case marks an extraordinary intrusion into the operation of state and local government in this country. Its impact can hardly be overstated.

A

Under our federal system, a State is generally free to allocate its governmental power to its political subdivisions as it wishes. A State may decide to permit its municipalities to exercise its police power without having to obtain approval of each law from the legislature. Such local self-government serves important state interests. It allows a state legislature to devote more time to statewide problems without being burdened with purely local matters, and allows municipalities to deal quickly and flexibly with local problems. But today's decision, by demanding extensive legislative control over municipal action, will necessarily diminish the extent to which a State can share its power with autonomous local governmental bodies.

This will follow from the plurality's emphasis on state legislative action, and the vagueness of the criteria it announces. First, it is not clear from the plurality opinion whether a municipal government's actions will be immune from the Sherman Act if they are merely "authorized" by a state legislature or whether they must be legislatively "directed" in order to enjoy immunity. While the plurality uses these terms interchangeably, they can have very different meanings. See Cantor v. Detroit Edison Co., 428 U.S., at 592-593. A municipality that is merely "authorized" by a state statute to provide a monopoly service thus cannot be certain it will not be subject to antitrust liability if it does so.

Second, the plurality gives no indication of how specifically the legislature's "direction" must relate to the "action complained of." Reference to the facts of this case will show how elusive the plurality's test is. Stripped to its essentials, the counterclaim alleged that the petitioners engaged in sham litigation, maintained their monopolies by debenture covenants, foreclosed competition by long-term supply contracts, and tied the sale of gas and water to the sale of electricity. Broadly speaking, these actions could be characterized as bringing lawsuits, issuing bonds, and providing electric and gas service, all of which are activities authorized by state statutes. But in affirming the judgment of the Court of Appeals the Court makes evident that it does not consider these statutes alone a sufficient "mandate" to the cities.

On the other hand, the plurality states that a city need not "point to a specific, detailed legislative authorization before it properly may assert a Parker defense to an antitrust suit." Ante, at 415. Thus, it seems that the petitioners need not identify a statute compelling each lawsuit, each contract, and each debenture covenant. But what intermediate showing of legislative authorization, approval, or command will meet the plurality's test I am unable to fathom.

Finally, state statutes often are enacted with little recorded legislative history, and the bare words of a statute will often be unilluminating in interpreting legislative intent. For example, do the Louisiana statutes permitting the petitioners to operate public utilities "contemplate" that the petitioners might tie the sale of gas to the sale of electricity? Do those statutes, indeed, "contemplate" that electric service will be provided to city residents on a monopoly basis? Without legislative history or relevant statutory language, any answer to these questions would be purely a creation of judicial imagination.

As a practical result of the uncertainties in today's opinions, and of the plurality's emphasis on state legislative action, a prudent municipality will probably believe itself compelled to seek passage of a state statute requiring it to engage in any activity which might be considered anticompetitive. Each time a city grants an exclusive franchise, or chooses to provide a service itself on a monopoly basis, or refuses to grant a zoning variance to a business, or even — as alleged in this case — brings litigation on behalf of its citizens, state legislative action will be necessary to ensure that a federal court will not subsequently decide that the activity was not "contemplated" by the legislature. Thus, the effect of today's decision is greatly to impair the ability of a State to delegate governmental power broadly to its municipalities. Such extensive interference with the fundamentals of state government is not a proper function of the federal judiciary.

B

Today's decision will cause excessive judicial interference not only with the procedures by which a State makes its governmental decisions, but with their substance as well. States should be "accorded wide latitude in the regulation of their local economies," New Orleans v. Dukes, 427 U.S. 297, 303, and in "the manner in which they will structure delivery of those governmental services which their citizens require." National League of Cities v. Usery, 426 U.S., at 847. The antitrust liability the Court today imposes on municipal governments will sharply limit that latitude.

First, the very vagueness and uncertainty of the new test for antitrust immunity is bound to discourage state agencies and subdivisions in their experimentation with innovative social and economic programs. In the exercise of their powers local governmental entities often take actions that might violate the antitrust laws if taken by private persons, such as granting exclusive franchises, enacting restrictive zoning ordinances, and providing public services on a monopoly basis. But a city contemplating such action in the interest of its citizens will be able to do so after today only at the risk of discovering too late that a federal court believes that insufficient statutory "direction" existed, or that the activity is "proprietary" in nature.

Second, the imposition of antitrust liability on the activities of municipal governments will allow the sort of wide-ranging inquiry into the reasonableness of state regulations that this Court has forsworn. For example, in New Orleans v. Dukes, supra, a city ordinance which, to preserve the character of a historic area, prohibited the sale of food from pushcarts unless the vendor had been in business for at least eight years, was challenged under the Equal Protection Clause of the Fourteenth Amendment. The Court upheld the constitutional validity of the ordinance. But it now appears that if Dukes had proceeded under the antitrust laws and claimed that the ordinance was an unreasonably anticompetitive limit on the number of pushcart vendors, he might well have prevailed unless New Orleans could establish that the Louisiana Legislature "contemplated" the exclusion of all but a few pushcart vendors from the historic area. The "wide latitude" of the States "in the regulation of their local economies," exercised in Dukes by the city to which this power to regulate had been delegated, could thus be wholly stifled by the application of the antitrust laws.

C

Finally, today's decision will impose staggering costs on the thousands of municipal governments in our country. In this case, a not atypical antitrust action, the respondent claimed that it had suffered damages of $180 million as a result of only one of the antitrust violations it alleged. Trebled, this amounts to $540 million on this claim alone, to be recovered from cities with a combined population (in 1970) of about 75,000. A judgment of this magnitude would assure bankruptcy for almost any municipality against which it might be rendered. Even if the petitioners ultimately prevail, their citizens will have to bear the rapidly mounting costs of antitrust litigation through increased taxes or decreased services. The prospect of a city closing its schools, discharging its policemen, and curtailing its fire department in order to defend an antitrust suit would surely dismay the Congress that enacted the Sherman Act.

For all of the reasons discussed in this opinion, I respectfully dissent.

MR. JUSTICE BLACKMUN, dissenting.

I join MR. JUSTICE STEWART'S dissent with the exception of Part II-B, but wish to note that I do not take his opinion as reaching the question whether petitioners should be immune under the Sherman Act even if found to have been acting in concert with private parties. To grant immunity to municipalities in such a circumstance would go beyond the protections previously accorded officials of the States themselves. See Parker v. Brown, 317 U.S. 341, 351-352 (1943) ("[W]e have no question of the state or its municipality becoming a participant in a private agreement or combination by others for restraint of trade, cf. Union Pacific R. Co. v. United States, 313 U.S. 450"). The Court of Appeals did not have the opportunity to rule on how a "conspiracy with private parties" exception to municipalities' general immunity should be limited, if indeed such an exception is appropriate at all. If the view that municipalities are not subject to the full reach of Sherman Act liability had commanded a majority, a remand for consideration of this more limited exception would be in order.

In light of the fact that the plurality and THE CHIEF JUSTICE have concluded that municipalities should be subject to broad Sherman Act liability, I must question the nonchalance with which the Court puts aside the question of remedy. Ante, at 402, and n. 22. It is a grave act to make governmental units potentially liable for massive treble damages when, however "proprietary" some of their activities may seem, they have fundamental responsibilities to their citizens for the provision of life-sustaining services such as police and fire protection. The several occasions in the past when the Court has found that Congress intended to subject municipalities and States to liability as "persons" or "corporations" do not provide the support for today's holding that the plurality opinion would pretend. Ante, at 400-402, and nn. 19-21. The Court cites previous constructions of the Elkins Act; the federal tax on sellers of alcoholic beverages; and the Shipping Act, 1916. But the financial penalties available under those Acts do not even approach the magnitude of the treble-damages remedy provided by the antitrust laws. Nor has the Court come to grips with the plainly mandatory language of § 4 of the Clayton Act, 15 U.S.C. § 15 (1976 ed.): "Any person who shall be injured in his business or property by reason of anything forbidden in the antitrust laws . . . shall recover threefold the damages by him sustained" (emphasis supplied), and the repeated occasions on which Congress has rejected proposals to make the treble-damages remedy discretionary. It is one thing to leave open the question of remedy if there is a conceivable defense to damages whose theory is consistent with the mandatory language of the Clayton Act ( e.g., in the case of private utilities subject to state tariffs, that their conduct was required by state law and hence was involuntary). See Cantor v. Detroit Edison Co., 428 U.S. 579, 614-615, n. 6 (1976) (opinion concurring in judgment). It is quite another to delay the question of remedy in the absence of any suggested basis for a defense, especially where the prospect of insolvency for petitioner cities would so threaten the welfare of their inhabitants. The sensible course, it seems to me, is to consider the range of liability in light of the range of defendants for whom Sherman Act penalties would be appropriate.