The United States Supreme Court case, United Transportation Union v. State Bar of Michigan (1970), centered around the issue of whether a labor union could provide legal services to its members through retained salaried attorneys. The State Bar of Michigan had previously prohibited this practice on grounds that it constituted unauthorized practice of law and violated professional ethics rules. However, the Supreme Court ruled in favor of the United Transportation Union, stating that such prohibition was unconstitutional as it infringed upon First Amendment rights to freedom of association and speech. The court held that unions have a constitutional right to hire lawyers for their members because this arrangement is part and parcel with collective bargaining activities protected by federal labor laws.

In the dissenting opinion for the United Transportation Union v. State Bar of Michigan case, Justice Black argued that prohibiting non-lawyers from representing union members in court violated First Amendment rights to freedom of speech and assembly. He contended that this prohibition was a form of economic protectionism for lawyers, rather than a measure designed to protect clients from incompetent representation. Furthermore, he believed it infringed upon workers' rights to choose their own representatives in legal matters. In his view, unions should be allowed to hire non-lawyer agents if they so desired because these individuals could potentially provide more affordable and accessible services compared with traditional attorneys. This would also allow unions greater flexibility in choosing who represents them based on factors such as familiarity with specific labor issues or personal rapport with union members.