Movements and parties have given rise to two largely separates specialties in the social sciences. This Element is an effort to link the two literatures, using evidence from American political development. It identifies five relational mechanisms governing movement/party relations: two of them short term, two intermediate term, and one long-term. It closes with a reflection on the role of movement/party relations in democratization and for democratic resilience.

1. What Was Happening Here?; 2. Moves Toward Fusion; 3. Movement/Party Relations in Critical Junctures; 4. Two Short-Term Linkage Mechanisms; 5. Two Intermediate-Level Mechanisms; 6. Movements, Parties, and Democracy.