In the case Gulf Refining Co. v. Fox, Tax Commissioner (1935), the U.S Supreme Court ruled in favor of Gulf Refining Company, a Pennsylvania corporation that operated gasoline stations in West Virginia but refined its petroleum products outside of the state. The court held that West Virginia's tax on wholesale distributors was unconstitutional as it violated both Due Process and Commerce Clauses of the Constitution by imposing an undue burden on interstate commerce and discriminating against out-of-state businesses. This decision affirmed that states cannot levy taxes which discriminate against or unduly burden interstate commerce, reinforcing principles established under previous rulings such as those made in Shaffer v Carter (1920) and International Shoe Co v Washington (1945).

In the dissenting opinion for Gulf Refining Co. v. Fox, Tax Commissioner, it was argued that the tax imposed by West Virginia on gasoline stored temporarily in the state before being exported to other states did not violate the Commerce Clause of the U.S Constitution. The dissenting justices believed that this case differed from previous cases where taxes were levied directly on goods in transit through a state or where they interfered with interstate commerce activities. They reasoned that since West Virginia's tax applied equally to all gasoline stored within its borders regardless of its final destination (whether within or outside of West Virginia), it could not be seen as discriminatory against interstate commerce and thus should be upheld.