Katzenbach v. McClung
Justice Clark wrote the majority opinion, with concurrences by Justices Black, Douglas, and Goldberg. In section 2 of the opinion, the Court agreed with McClung that Ollie's itself had virtually no effect on interstate commerce. In section 4 of the opinion, the Court held that racial discrimination in restaurants had a significant impact on interstate commerce, and therefore Congress has the power to regulate this conduct under the Commerce Clause. The Court's conclusion was based on extensive Congressional hearings on the issue.