In Humphrey et al. v. Moore et al., the Supreme Court ruled on a dispute between union members and their leadership over a merger agreement with another union that would alter voting rights within the organization. The plaintiffs argued that this violated their contract, while the defendants contended they had broad authority to make such decisions under federal labor law. The court sided with the defendants, holding that unions have wide discretion in managing internal affairs as long as they act in good faith and without discrimination against any of its members. This decision affirmed unions' right to self-governance and clarified how far-reaching those powers could be when it comes to making changes affecting membership rights.

In the dissenting opinion for Humphrey et al. v. Moore et al., Justice Douglas argued that the union's decision to merge seniority lists was a breach of its duty of fair representation, as it disproportionately disadvantaged certain members without their consent or input. He contended that unions should not have unchecked power to make decisions affecting member rights and interests, especially when those decisions could result in job loss or demotion for some members while benefiting others. In his view, this case represented an overreach by the majority in granting such broad authority to unions at the expense of individual workers' rights and protections under labor law.