As legal protections for labor organizing face existential threats, the American labor movement must confront a deeper challenge: the erosion of social norms that once condemned union-busting as morally wrong.

Antitrust enforcers have recently begun to treat abusive labor practices — such as worker misclassification and noncompete agreements — as unfair methods of competition. But this approach is not new. Since the early twentieth century, labor advocates, legislators, and judges have all recognized that when employers mistreat their workers to obtain cost advantages, they harm both workers and their competitors.