Michigan Law Review, Vol. 79, No. 1 (November 1980), pp. 113-171


The state tax field is experiencing a renaissance of sorts. The Supreme court has displayed a renewed interest in the area, handing down an unusual number of significant decisions addressed to the constitutional restraints on state tax power. State courts have exhibited a similar revival of interest in these problems through an outpouring of uncharacteristically thoughtful opinions concerning state taxation of multistate and multinational enterprise. Congress, whose concern with state taxation of interstate and foreign commerce has been sporadic, is again considering legislation that would limit state taxing authority in these domains. Even the executive branch, which seldom intervenes in state tax controversies that do not involve the federal government's own tax liability, has become embroiled in the broad conflict regarding the appropriate scope of state tax power. The states, acting independently and through the Multistate Tax Commission, have been intensifying their efforts to tax interstate and international business. And corporate taxpayers, whose dollars are ultimately the focus of all this activity, have become increasingly vocal in seeking relief from state taxing schemes they regard as unduly burdensome. Congress has rarely limited state tax power; existing limitations have been shaped largely by the Supreme Court. However, the Court's recent decisions have generally afforded states substantial leeway in taxing interstate business, and experience suggests that Congress can be persuaded to act in the climate created by such decisions. Congress enacted the most important piece of federal legislation restricting state tax authority as a direct response to a Supreme Court decision that allegedly construed state tax power so expansively as to cripple interstate business. Moreover, the Court in its recent opinions has invited Congress to act if it is unhappy with the Court's hands-off attitude. The Court's two most recent decisions delineating the constitutional constraints on state taxation of interstate and foreign commerce should be viewed against this background. In Mobile Oil Corp. v. Commissioner of Taxes and Exxon Corp. v. Wisconsin Department of Revenue, the Court upheld state income taxes imposed on multistate and multinational corporations. The opinions reflect a generous view of state taxing authority. Because they explore a number of sensitive issues that have been brewing in the state courts and administrative agencies for years, the opinions are important in their own right. They assume additional importance because they contribute to a climate that may lead Congress to take away from the states what the Court has apparently allowed them. The purpose of this Article is twofold: first, to analyze the Mobile and Exxon decisions; second, to consider the congressional reaction they may engender.