Under what conditions do state policies to include or exclude opposition groups lead them to radicalize or to moderate instead? To contextualize contradictory arguments in the literature, I return to the colonial origins of state-opposition antagonisms. I explore how colonial authorities structured nascent state apparatuses to view social movements with suspicion, turning them into "opposition" movements, initiating a long cycle of an exclusive - and initially repressive - relationship. From this starting point, I develop a framework that centers the cross-generational reproduction of factional tensions within opposition groups. Exclusion exacerbates tensions between moderate and radical factions, forcing open debates about opposition strategies. Historically, this favored moderate factions who survived by avoiding confrontation. Yet their prioritization of survival led them to compromise with incumbent regimes who contained their influence and limited reform. The failure of moderate opposition actors to make change has led to the rise of more creation radical forms of resistance among new opposition actors. To highlight this “pendulum” effect, I examine the trajectory of the Egyptian Islamist, Iraqi Communist, and Palestinian Nationalist movements. Drawing on Paul Pierson’s work, I show that scholars in the literature have studied the causes of moderation and radicalization in snapshots rather than in frameworks that account for the long-term, developing relationships between states and opposition actors.