In the 1985 case Wardair Canada Inc. v. Florida Department of Revenue, the U.S Supreme Court was asked to determine whether a Canadian airline company, Wardair Canada Inc., should be exempt from paying taxes on aviation fuel purchased in Florida for international flights. The State of Florida had imposed tax on fuel purchases made by foreign airlines while domestic airlines were granted an exemption under federal law and treaties between the United States and other countries. The court ruled that such taxation did not violate any treaty or constitutional provision as it was applied uniformly to all carriers regardless of their nationality or destination. Therefore, despite being a foreign corporation operating primarily outside U.S borders, Wardair was required to pay tax on its fuel purchases within Florida.

The dissenting opinion in the case of Wardair Canada Inc. v. Florida Department of Revenue argued that the majority's decision was inconsistent with previous rulings and principles established by the Court regarding state taxation on interstate commerce. The dissent contended that Florida's tax did not discriminate against foreign or interstate commerce, as it applied equally to all airlines operating within its borders, regardless of their origin or destination points. Furthermore, they believed that this tax did not create any undue burden on interstate trade since it was based solely on fuel consumption within Florida’s jurisdiction and thus fairly apportioned among users according to their use of state resources. They also pointed out that there were no multiple taxes involved which could lead to cumulative burdens for businesses engaged in interstate activities because only one state -Florida- imposed a tax on jet fuel used within its boundaries.