457 U.S. 624 (1982)
Edgar v. MITE Corp.
Does the Illinois Business Take-Over Act violate the Commerce Clause by directly burdening and regulating interstate commerce, and/or is it preempted by the federal Williams Act under the Supremacy Clause?
Dormant Commerce Clause: A state law that directly regulates interstate commerce or has the practical effect of controlling commerce wholly outside the state is per se invalid. Where a statute regulates evenhandedly to effectuate a legitimate local interest and only incidentally affects interstate commerce, it is evaluated under Pike balancing and must be struck down if the burden on interstate commerce is clearly excessive in relation to the putative local benefits. Supremacy Clause (preemption): A state law is preempted if it conflicts with federal law, stands as an obstacle to the accomplishment and execution of Congress's full purposes and objectives, or intrudes upon a field Congress intended to occupy. The Williams Act reflects a federal policy of neutrality in tender offers—aimed at disclosure and shareholder choice without tipping the scales toward target management or offerors.
Affirmed. A majority of the Court held that the Illinois Business Take-Over Act violates the Commerce Clause because it directly burdens and regulates interstate commerce and its burdens are clearly excessive relative to local benefits. A plurality also concluded that the Act is preempted by the Williams Act.
MITE is a leading dormant Commerce Clause case on state regulation of national securities transactions. It teaches that states cannot project their laws to control out-of-state transactions or impose burdens that balkanize the national market. For securities regulation, it underscores the Williams Act's policy of shareholder-focused neutrality and limits state efforts that tip the balance toward management or obstruct tender offers. The case spurred the redesign of state anti-takeover statutes: later "second-generation" laws (e.g., control share, fair price statutes) were crafted to avoid extraterritorial reach and to align with internal corporate governance, facilitating the Supreme Court's later approval in CTS Corp. v. Dynamics Corp. of America (1987).