The Central Machinery Co. v. Arizona State Tax Commission case in 1979 revolved around the issue of tax discrimination against interstate commerce, which is prohibited by the Commerce Clause of the U.S. Constitution. The Supreme Court ruled in favor of Central Machinery Company, an out-of-state business that had been subjected to a use tax on its equipment rentals within Arizona state borders while similar local businesses were exempt from such taxes under state law. The court held that this differential treatment constituted unlawful discrimination against interstate commerce and was thus unconstitutional as it violated the Commerce Clause's principle of maintaining free trade among states without undue burdens or advantages for any particular entity based on their location or origin.

In the dissenting opinion for Central Machinery Co. v. Arizona State Tax Commission, Justice Brennan disagreed with the majority's decision that Arizona's use tax did not violate the Commerce Clause of the U.S. Constitution. He argued that this ruling contradicted previous decisions which held that a state could not impose a use tax on goods purchased out-of-state if it exempted similar in-state purchases from sales taxes, as doing so would discriminate against interstate commerce and favor local businesses over their out-of-state competitors. In his view, by allowing Arizona to apply its use tax to machinery bought outside of the state while exempting similar equipment sold within its borders from sales taxes, this decision effectively permitted such discriminatory taxation practices and undermined protections provided by the Commerce Clause.