validity of the statute on both constitutional and federal statutory grounds."

During the ensuing nine months, six other oil companies instituted comparable actions. Three of these plaintiffs, or their subsidiaries, sell their gasoline in Maryland exclusively through company-operated stations. These refiners, using trade names such as "Red Head" and "Scot," concentrate largely on high-volume sales with prices consistently lower than those offered by independent dealer-operated major brand stations. Testimony presented by these refiners indicated that company ownership is essential to their method of private brand, low-priced competition. They therefore joined Exxon in its attack on the divestiture provisions of the Maryland statute.

The three other plaintiffs, like Exxon, sell major brands primarily through dealer-operated stations, although they also operate at least one retail station each. They, too, challenged the statute's divestiture provisions, but, in addition, they specially challenged the requirement that "voluntary allowances" be extended uniformly to all retail service stations supplied in the State. Although not defined in the statute, the term "voluntary allowances" refers to temporary price reductions granted by the oil companies to independent dealers who

"Exxon presented nine arguments, both constitutional and statutory. It contended that the statute was arbitrary and irrational under the Due Process Clause; constituted an unconstitutional taking of property without just compensation; denied it, in two distinct ways, the equal protection of the laws; constituted an unlawful delegation of legislative authority; was unconstitutionally vague; discriminated against and burdened interstate commerce; and was pre-empted by the Robinson-Patman Act and the Federal Emergency Petroleum Allocation Act of 1973. Id., at 14-16.

• These plaintiffs are Continental Oil Co. (and its subsidiary Kayo Oil Co.), Commonwealth Oil Refining Co. (and its subsidiary Petroleum Marketing Corp.), and Ashland Oil Co.

'These plaintiffs are Phillips Petroleum Co., Shell Oil Co., and Gulf Oil Corp.

are injured by local competitive price reductions of competing retailers. The oil companies regard these temporary allowances as legitimate price reductions protected by § 2 (b). In advance of trial, Exxon, Shell, and Gulf moved for a partial summary judgment declaring this portion of the Act invalid as in conflict with § 2 (b).

The Circuit Court granted the motion, and the trial then focused on the validity of the divestiture provisions. As brought out during the trial, the salient characteristics of the Maryland retail gasoline market are as follows: Approximately 3,800 retail service stations in Maryland sell over 20 different brands of gasoline. However, no petroleum products are produced or refined in Maryland, and the number of stations actually operated by a refiner or an affiliate is relatively small, representing about 5% of the total number of Maryland retailers.

The refiners introduced evidence indicating that their ownership of retail service stations has produced significant benefits for the consuming public. Moreover, the three refiners that now market solely through company-operated stations may elect to withdraw from the Maryland market altogether if the statute is enforced. There was, however, no evidence that the total quantity of petroleum products shipped into Maryland would be affected by the statute.10 After trial, the Circuit Court held the entire statute invalid, primarily on substantive due process grounds.

The Maryland Court of Appeals reversed, rejecting all of the refiners' attacks against both the divestiture provisions and

* See 279 Md., at 445-446, 370 A. 2d, at 1121–1122.

9

• Id., at 418-420, 370 A. 2d, at 1107-1108.

10 The Court of Appeals stated that the statute "would not in any way restrict the free flow of petroleum products into or out of the state." Id., at 431, 370 A. 2d, at 1114. While the evidence in the record does not directly support this assertion, it is certainly a permissible inference to be drawn from the evidence, or lack thereof, presented by the appellants. See Reply Brief for Appellants in No. 77-64, p. 7.

the voluntary-allowance provision. Most of those attacks are not pursued here; " instead, appellants have focused their appeals on the claims that the Maryland statute violates the Due Process and Commerce Clauses and that it is in conflict with the Robinson-Patman Act.

II

Appellants' substantive due process argument requires little discussion." The evidence presented by the refiners may cast some doubt on the wisdom of the statute, but it is, by now, absolutely clear that the Due Process Clause does not empower the judiciary "to sit as a 'superlegislature to weigh the wisdom of legislation'. . . . ." Ferguson v. Skrupa, 372 U. S. 726, 731 (citation omitted). Responding to evidence that producers and refiners were favoring company-operated stations in the allocation of gasoline and that this would eventually decrease the competitiveness of the retail market, the State enacted a law prohibiting producers and refiners from operating their own stations. Appellants argue that this response is irrational and that it will frustrate rather than further the State's desired goal of enhancing competition. But, as the Court of Appeals observed, this argument rests simply on an evaluation of the economic wisdom of the statute, 279 Md., at 428, 370 A. 2d, at 1112, and cannot override the State's authority "to legislate against what are found to be injurious practices in their internal commercial and business affairs...." Lincoln Federal Labor Union v. Northwestern Iron & Metal Co., 335 U. S. 525, 536.13 Regardless of the ultimate economic

11 See n. 5, supra.

12 Indeed, although the Circuit Court's decision rested primarily on the substantive due process claim, only appellants Continental Oil and its subsidiary, Kayo Oil, press that claim here.

13 It is worth noting that divestiture is by no means a novel method of economic regulation, and is found in both federal and state statutes. To date, the courts have had little difficulty sustaining such statutes against a substantive due process attack. See, e. g., Paramount Pictures,

efficacy of the statute, we have no hesitancy in concluding that it bears a reasonable relation to the State's legitimate purpose in controlling the gasoline retail market, and we therefore reject appellants' due process claim.

III

Appellants argue that the divestiture provisions of the Maryland statute violate the Commerce Clause in three ways: (1) by discriminating against interstate commerce; (2) by unduly burdening interstate commerce; and (3) by imposing controls on a commercial activity of such an essentially interstate character that it is not amenable to state regulation.

Plainly, the Maryland statute does not discriminate against interstate goods, nor does it favor local producers and refiners. Since Maryland's entire gasoline supply flows in interstate commerce and since there are no local producers or refiners, such claims of disparate treatment between interstate and local commerce would be meritless. Appellants, however, focus on the retail market, arguing that the effect of the statute is to protect in-state independent dealers from out-of-state competition. They contend that the divestiture provisions "create a protected enclave for Maryland independent dealAs support for this proposition, they rely on the fact that the burden of the divestiture requirements falls solely on interstate companies. But this fact does not lead, either logically or as a practical matter, to a conclusion that the State is discriminating against interstate commerce at the retail level.

ers

99 14

As the record shows, there are several major interstate marketers of petroleum that own and operate their own retail

Inc. v. Langer, 23 F. Supp. 890 (ND 1938), dismissed as moot, 306 U. S. 619; see generally Comment, Gasoline Marketing Practices and "Meeting Competition" under the Robinson-Patman Act, 37 Md. L. Rev. 323, 329 n. 44 (1977).

14 Brief for Appellants in No. 77-10, p. 27.

gasoline stations.15 These interstate dealers, who compete directly with the Maryland independent dealers, are not affected by the Act because they do not refine or produce gasoline. In fact, the Act creates no barriers whatsoever against interstate independent dealers; it does not prohibit the flow of interstate goods, place added costs upon them, or distinguish between in-state and out-of-state companies in the retail market. The absence of any of these factors fully distinguishes this case from those in which a State has been found to have discriminated against interstate commerce. See, e. g., Hunt v. Washington Apple Advertising Comm'n, 432 U. S. 333; Dean Milk Co. v. Madison, 340 U. S. 349. For instance, the Court in Hunt noted that the challenged state statute raised the cost of doing business for out-of-state dealers, and, in various other ways, favored the in-state dealer in the local market. 432 U. S., at 351-352. No comparable claim can be made here. While the refiners will no longer enjoy their same status in the Maryland market, in-state independent dealers will have no competitive advantage over out-of-state dealers. The fact that the burden of a state regulation falls on some interstate companies does not, by itself, establish a claim of discrimination against interstate commerce.16

15 For instance, as of July 1, 1974, such interstate, nonrefining or nonproducing, companies as Sears, Roebuck & Co., Hudson Oil Co., and Pantry Pride operated retail gas stations in Maryland. App. 190-191. Hudson has, however, recently acquired a refinery. See Brief for Appellants in No. 77-10, p. 33 n. 17.

16 If the effect of a state regulation is to cause local goods to constitute a larger share, and goods with an out-of-state source to constitute a smaller share, of the total sales in the market-as in Hunt, 432 U. S., at 347, and Dean Milk, 340 U. S., at 354-the regulation may have a discriminatory effect on interstate commerce. But the Maryland statute has no impact on the relative proportions of local and out-of-state goods sold in Maryland and, indeed, no demonstrable effect whatsoever on the interstate flow of goods. The sales by independent retailers are just as much a part of