[1] The challengers, including Exxon, claimed that the law violated the Dormant Commerce Clause.

Justice Stevens wrote for the majority, which disagreed with Exxon et al.: "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."

To combat this type of business, Maryland passed a law that prohibited producers or refiners from operating gasoline stations in Maryland, and required producers and refiners extend temporary price cuts to the stations they supplied.

(1) Does Maryland's statute prohibiting the control of both the production and distribution of oil violate the Due Process and Commerce Clauses of the Constitution?

This case is an exception to the rules set forth in Pike v. Bruce Church, Inc.. Justice Blackmun, with the only vote in favor of Exxon, wrote the dissenting opinion for the court.