The case of American Federation of Labor et al. v. American Sash & Door Co. et al., 1948, revolved around the issue of labor unions and their right to picket businesses for union recognition and closed shops (workplaces where only union members can be hired). The Supreme Court ruled in favor of the American Federation of Labor, stating that peaceful picketing by a labor organization for recognition from an employer is protected under the First Amendment's guaranteeing freedom of speech. This ruling was significant as it upheld workers' rights to organize and protest peacefully without fear of legal repercussions.

In the dissenting opinion for the American Federation of Labor v. American Sash & Door Co., Justice Frankfurter, joined by Justices Douglas and Murphy, argued that the majority's decision was a departure from established principles of federalism and labor law. They contended that Congress did not intend to preempt state laws regarding labor disputes when it passed the National Labor Relations Act (NLRA). The dissenters believed that states should be allowed to regulate local economic activities unless they conflict with federal law or policy. They also pointed out inconsistencies in how preemption had been applied in previous cases involving similar issues. Furthermore, they disagreed with the majority's interpretation of 'affecting commerce' within NLRA as overly broad and warned against judicial overreach into legislative territory.