In the 1960 case of Local 357, International Brotherhood of Teamsters, Chauffeurs, Warehousemen and Helpers of America v. National Labor Relations Board (NLRB), the Supreme Court ruled in favor of NLRB. The dispute arose when a union demanded that an employer hire only its members for certain jobs. This was seen as a violation by the NLRB who argued it violated Section 8(b)(2) and (1)(A) of the National Labor Relations Act which prohibits unions from causing or attempting to cause employers to discriminate against employees for not being part of a union. The Supreme Court agreed with this interpretation stating that such demands were indeed discriminatory under federal labor law because they sought to limit employment opportunities based on union membership status rather than qualifications or skills.

In the dissenting opinion for the case of Local 357, International Brotherhood of Teamsters, Chauffeurs, Warehousemen and Helpers of America v. National Labor Relations Board (1960), Justice Frankfurter disagreed with the majority's interpretation that an employer is obligated to bargain over issues related to union security even when a valid contract exists between them. He argued that this interpretation was not in line with previous court decisions or legislative history surrounding labor relations law. Furthermore, he contended that it would lead to unnecessary disputes and disruptions in established bargaining relationships by allowing unions to demand negotiations on settled matters at any time. The justice also expressed concern about potential implications for freedom of contract principles if employers were forced into continuous bargaining over already agreed-upon terms.