In H. K. Porter Co., Inc., Disston Division-Danville Works v. National Labor Relations Board et al., 1969, the U.S Supreme Court ruled that the National Labor Relations Board (NLRB) does not have the authority to compel employers and unions to agree on specific contract terms during collective bargaining negotiations. The case arose when H.K Porter Company refused to include a union shop clause in its agreement with United Steelworkers of America AFL-CIO, despite an NLRB order mandating it do so after a majority of employees voted for union representation. The court held that while Section 8(d) of the National Labor Relations Act requires both parties to bargain in good faith over mandatory subjects such as wages, hours, and other conditions of employment; it does not allow NLRB or courts to force either party into agreeing on any substantive contractual provisions regarding these issues.

In the dissenting opinion for H.K. Porter Co., Inc., Disston Division-Danville Works v. National Labor Relations Board et al, Justice Douglas argued that the majority's decision undermined the power of the National Labor Relations Board (NLRB) to enforce collective bargaining agreements and protect workers' rights. He contended that by refusing to allow NLRB to mandate specific terms in a labor agreement, such as dues-checkoff provisions, it limited its ability to rectify unfair labor practices effectively. Douglas believed this ruling contradicted previous court decisions which upheld NLRB’s authority in similar situations and could potentially weaken unions’ negotiating powers with employers significantly.