In the 1974 case Connell Construction Co., Inc. v. Plumbers & Steamfitters Local Union No. 100, the U.S Supreme Court ruled that a union's agreement with an employer to only subcontract work to other firms employing members of that union was in violation of antitrust laws, specifically Section 8(e) of the National Labor Relations Act (NLRA). The court held that such agreements could potentially restrain trade and competition by limiting opportunities for non-union contractors or those affiliated with different unions. While acknowledging labor organizations' exemption from certain aspects of antitrust legislation under federal law, this decision clarified that such exemptions did not extend to all activities undertaken by unions and their associated collective bargaining processes.

In the dissenting opinion for Connell Construction Co., Inc. v. Plumbers & Steamfitters Local Union No. 100, Justice Douglas argued that the majority's decision was a departure from established antitrust law principles and an unwarranted intrusion into labor relations policy set by Congress. He contended that the Sherman Act should not be applied to collective bargaining agreements between unions and employers because such application would undermine workers' rights to organize and bargain collectively as protected under federal labor laws like National Labor Relations Act (NLRA). According to him, this case involved a legitimate union activity aimed at achieving higher wages and better working conditions for its members rather than an anti-competitive conspiracy in restraint of trade prohibited by antitrust laws.