In the case of National Labor Relations Board v. Plasterers' Local Union No. 79, Operative Plasterers' & Cement Masons' International Association, AFL-CIO et al., the U.S Supreme Court ruled in favor of the National Labor Relations Board (NLRB). The dispute arose when a union attempted to force an employer into signing a contract that would require all employees to join their union within eight days or be fired - this was deemed as unfair labor practice under Section 8(b)(2) and (1)(A) of the National Labor Relations Act. The court held that even though no employee had been adversely affected yet by this clause, it still constituted an unfair labor practice because it placed pressure on employers and employees alike to conform with union membership requirements against their will. This ruling reinforced workers’ rights not to join unions if they choose not to do so.

In the dissenting opinion for the National Labor Relations Board v. Plasterers' Local Union No. 79 case, it was argued that the majority's decision to uphold an order by the NLRB against a union engaging in secondary boycotts was incorrect and overstepped its authority. The dissent pointed out that Congress had not intended to prohibit all forms of secondary pressure when they enacted labor laws but rather sought to strike a balance between protecting neutral employers from undue harm and allowing unions some leeway in their fight for better working conditions. They believed this delicate balance had been disrupted by the majority's ruling which seemed to favor businesses over workers' rights, thereby undermining one of labor law’s primary purposes: promoting industrial peace through collective bargaining.