In Tully et al. v. Mobil Oil Corp. et al., 1981, the U.S Supreme Court addressed a dispute over New York State's Petroleum Business Tax (PBT). The plaintiffs, oil companies including Mobil Oil Corporation, argued that the PBT violated the Commerce Clause of the Constitution by discriminating against interstate commerce as it imposed higher taxes on petroleum products imported into New York from other states compared to those produced within New York state itself. The court ruled in favor of the oil companies and found that certain provisions of PBT did indeed violate the Commerce Clause because they provided tax advantages for local production at an expense to out-of-state producers and suppliers.

In the dissenting opinion for Tully et al. v. Mobil Oil Corp., Justice Blackmun argued that New York's Petroleum Business Tax (PBT) did not violate the Commerce Clause of the U.S. Constitution, contrary to what was concluded by majority decision. He contended that PBT is a tax on petroleum businesses' privilege of operating in New York and it does not discriminate against interstate commerce as it applies equally to both local and out-of-state companies involved in petroleum business within state borders. Furthermore, he disagreed with the majority’s view that PBT is an impermissible multiple taxation because other states could also impose similar taxes without causing any constitutional issues under Complete Auto Transit test which allows a state to levy tax if it has substantial nexus with taxpayers’ activities, is fairly apportioned, doesn't discriminate against interstate commerce and relates reasonably to services provided by State.