How do unions that represent similar constituencies and fight for comparable goals come to embrace radically different relationships to the state and party politics? Drawing on Collier and Collier’s (1991) concept of the dual dilemma, that is, whether to collaborate with the state and risk co-optation or reject such collaborations and risk being sidelined, I analyze teachers’ unions political strategy in São Paulo (APEOESP) and Oaxaca (Local 22). In São Paulo, strategy centers on taking state power by building political parties that fight for working-class interests. In Oaxaca, the rise of the democratic teachers’ movement was a rejection of state power and an attempt to build autonomy from political parties. I argue that teachers chose these contrasting strategies during the late-1970s and early 1980s, due to their experiences of the legacies of labor incorporation under authoritarian regimes. The internal political practices established during this transitional period, when reform movements took control of the unions in both countries, continue to shape teachers’ strategies to the present. These findings suggest that union strategies regarding how to interact with the state are deeply shaped by previous state-labor relations and that unionists’ responses to the dilemma about whether to take or reject state power will directly shape their interpretations of ongoing political challenges.