Exxon Corp. v. Governor of Maryland

A Maryland statute provides that a producer or refiner of petroleum products (1) may not operate any retail service station within the State, and (2) must extend all “voluntary *120allowances” uniformly to all service stations it supplies.1 The questions presented are whether the statute violates either the Commerce or the Due Process Clause of the Constitution of the United States, or is directly or indirectly pre-empted by the congressional expression of policy favoring vigorous competition found in § 2 (b) of the Clayton Act, 38 Stat. 730, as amended by the Robinson-Patman Act, 49 Stat. 1526.2…