AbstractIn the early 21st century, teachers' union mobilization was widespread throughout the United States. Decrying low salaries, restrictions on labor rights, and more, teachers' unions engaged in large‐scale tactics such as massive strikes, public protests, and successful ballot campaigns. In this article, I demonstrate that by sharing characteristics of both social movement organizations and interest groups, teachers' unions are well suited to respond to political threats. Teachers' unions are large, longstanding organizations with the resources necessary to use a wide variety of tactics. Teachers' relationships with parents and the local community provide strong potential for alliances, and teachers can leverage their professional identity and expertise to help establish legitimacy in educational policy conversations. Ultimately, however, the future of teachers' unions depends upon sustained worker and ally activism beyond the current wave of mobilization.