Commonwealth Edison Co. v. Montana

Summary

The Court upheld Montana's coal severance tax against Commerce Clause and Supremacy Clause challenges. It held that severance taxes are subject to the practical, four-part Commerce Clause inquiry, but Montana's tax had a substantial nexus, was fairly apportioned, did not discriminate against interstate commerce, and was fairly related to the taxpayers' in-state activities and the general benefits of government. The Court also held that federal leasing and energy statutes neither prohibited the tax nor preempted it. Justice Blackmun, dissenting, would have allowed a trial on whether the tax imposed an excessive burden on interstate commerce, while Justice White concurred with reservations about the tax's potential burden.