The U.S. Supreme Court case of Gerald A. Lewis, Comptroller of the State of Florida v. Continental Bank Corporation et al., 1989, revolved around a dispute over state taxation on banks and financial institutions operating within its borders. The State of Florida had imposed an intangible personal property tax on non-Florida banks for their ownership interest in local branches but exempted domestic (Florida-based) corporations from this tax. Continental Bank Corporation and other out-of-state banking institutions challenged this as discriminatory under the Commerce Clause which prohibits states from favoring local commerce over interstate commerce. In a unanimous decision, the Supreme Court ruled in favor of the plaintiffs stating that Florida's differential treatment between domestic and foreign corporations was unconstitutional because it violated principles established by both Complete Auto Transit Inc v Brady (1977), which set forth four criteria to evaluate constitutionality under Commerce Clause, and Armco Inc v Hardesty (1984), where any form of discrimination against interstate commerce is generally deemed invalid unless justified by factors unrelated to economic protectionism.

In the dissenting opinion for Gerald A. Lewis, Comptroller of the State of Florida v. Continental Bank Corporation et al., Justice Brennan, joined by Justices Marshall and Blackmun, disagreed with the majority's interpretation of federal banking law as preempting state restrictions on interstate banking activities. They argued that Congress did not intend to prevent states from imposing their own limitations on bank expansion when it passed legislation regulating national banks' ability to establish out-of-state branches. The dissenters believed that allowing states to regulate these activities would promote a dual system of state and federal regulation in line with historical practice and congressional intent. They also expressed concern about potential negative effects on local economies if large national banks were allowed unrestricted expansion into new markets without regard for state laws designed to protect smaller community-based institutions.