This study traces the development of union loyalties among community college professors. Assuming that activism is motivated by contextual and ideological factors, the paper analyzes the ways that social networks, collegiate workplaces, and framing practices transform political bystanders into committed union members. Using data from a study of junior college professors in Kentucky (N = 329), the study finds that union participation is strongly linked to a distrust of campus administrators and having pro‐union friends and colleagues. Likewise, perceptions of union efficacy, a liberal identity as well the professor’s education level predicted the actual joining of their campus’ faculty union.