In the 1986 case National Labor Relations Board v. International Brotherhood of Electrical Workers, Local 340, the U.S. Supreme Court ruled in favor of the National Labor Relations Board (NLRB). The dispute centered around whether a union could require its members to pay fines for working during a strike. The NLRB argued that such fines were illegal under federal labor law as they infringed on workers' rights not to participate in strikes if they so choose. The court agreed with this interpretation and held that while unions have broad powers to manage their internal affairs and discipline members, these powers do not extend to punishing those who decide against participating in union-sanctioned strikes.

In the dissenting opinion for the National Labor Relations Board v. International Brotherhood of Electrical Workers, Local 340 case, Justice Brennan disagreed with the majority's interpretation of Section 8(b)(4) of the National Labor Relations Act (NLRA). He argued that this section should not be read to prohibit a union from fining its members who cross picket lines during a lawful strike. According to him, such an interpretation undermines Congress' intent in passing NLRA - protecting workers' rights and promoting industrial peace through collective bargaining. He believed that allowing unions to enforce discipline among their members is crucial for maintaining solidarity during strikes and ensuring successful negotiations with employers. Moreover, he pointed out that there were no clear indications from Congress suggesting it intended to limit unions’ internal disciplinary powers when it enacted Section 8(b)(4). Therefore, he concluded that unless explicitly stated by Congress or clearly implied from legislative history or statutory language itself, courts should refrain from interpreting labor laws in ways restricting union self-governance.