In Reed v. United Transportation Union et al., the U.S Supreme Court ruled that a union's imposition of a fine on members who crossed picket lines during a strike did not violate federal labor law. The case arose when several members of the United Transportation Union were fined by their local chapter for crossing picket lines to work during an authorized strike against Southern Pacific Company in 1979. These workers sued, arguing that such fines violated Section 101(a)(5) of the Labor-Management Reporting and Disclosure Act (LMRDA), which prohibits unions from limiting "the right of any member thereof to institute an action in any court." However, the Supreme Court disagreed with this interpretation and held that LMRDA does not protect union members from being disciplined by their union for crossing picket lines during strikes. The court reasoned that allowing such discipline is consistent with Congress' intent to balance individual rights against collective interests within labor organizations.

In the dissenting opinion for Reed v. United Transportation Union et al., Justice Blackmun disagreed with the majority's view that a union could lawfully exclude nonmembers from voting in ratification elections, even when those elections determined critical aspects of their employment conditions. He argued that such exclusion violated the Railway Labor Act’s requirement for unions to represent all employees fairly and without discrimination. The justice believed this duty extended to include nonmember participation in contract ratification votes because these decisions significantly impacted all workers' terms and conditions of employment. Furthermore, he contended that allowing only union members to vote created an unjustifiable burden on nonmembers’ rights not to associate with the union, thus infringing upon their First Amendment rights.