The United Automobile, Aircraft & Agricultural Implement Workers of America v. Wisconsin Employment Relations Board case in 1955 revolved around the issue of whether a state could constitutionally regulate labor union activities that were already regulated by federal law. The Supreme Court ruled in favor of the Wisconsin Employment Relations Board, stating that states have concurrent jurisdiction with the National Labor Relations Board (NLRB) over labor disputes and can enforce their own laws against unfair labor practices as long as they do not conflict with federal legislation. This decision was based on an interpretation of Section 14(b) of the Taft-Hartley Act which allows states to enact "right-to-work" laws prohibiting compulsory union membership. The court held that this provision did not preclude states from also regulating other aspects of union activity within their borders.

In the dissenting opinion for this case, Justice Frankfurter argued that the majority's decision undermined state sovereignty by limiting Wisconsin's ability to regulate labor disputes within its borders. He contended that states should have broad authority to manage their own affairs and maintain public order, including regulating strikes and other forms of industrial action. The justice also expressed concern about federal overreach into areas traditionally controlled by states, arguing that it could lead to a concentration of power in Washington D.C., which he believed was contrary to the principles of federalism enshrined in the Constitution. Furthermore, he disagreed with the majority’s interpretation of national labor laws as preempting state law on this issue; instead asserting they were designed to supplement rather than supplant local regulations.