In the case of Local No. 207, International Association of Bridge, Structural and Ornamental Iron Workers Union v. Perko in 1962, the U.S Supreme Court ruled on a dispute involving union membership and employment rights. The plaintiff, Perko was an ironworker who had been expelled from his local union for working with non-union workers during a strike against another company. After expulsion from the union he was unable to find work due to a clause in collective bargaining agreements that required employers to hire only union members. He sued his former local and international unions under federal antitrust laws claiming they were monopolizing labor supply by restricting access to jobs based on their membership rules. The court held that labor unions are exempted from antitrust laws when pursuing legitimate objectives such as maintaining solidarity among its members or achieving beneficial terms through collective bargaining agreements; thus ruling in favor of the defendant -the Unions-. However it also stated that if these actions result into serious economic injury then state courts can provide remedies under common law principles.

In the dissenting opinion for Local No. 207, International Association of Bridge, Structural and Ornamental Iron Workers Union v. Perko (1962), Justice Harlan argued that the majority's decision to allow a union member to sue his union in state court over an internal dispute was incorrect. He believed this ruling undermined federal labor policy by allowing states to interfere with private agreements between unions and their members, which are meant to be self-regulating under federal law. Furthermore, he contended that such disputes should be resolved through arbitration rather than litigation as it is more efficient and less disruptive for both parties involved. Finally, he expressed concern about the potential implications of this decision on future cases involving similar issues.