The Establishment of Party Policy Committees in the U.S. Senate: Coordination, Not Coercion *

Objective We seek to determine if institutional changes designed to increase intraparty coordination influenced observed levels of party unity in the U.S. Senate. In particular, we test competing claims regarding the effects of establishing party policy committees following the adoption of the Legislative Reorganization Act of 1946. Methods First, we examine Congress at the vote level by looking at the overall proportion of votes that could be classified as “party unity votes” before and after the establishment of the policy committees. Second, we employ a micro‐level analysis by examining individual senators’ procedural party support scores. Results We find that members of the majority party were more likely to have higher levels of procedural unity after the adoption of policy committees. Conclusion The establishment of party policy committees in the Senate played a role in helping party leaders coordinate activities, advance a legislative agenda, and maintain high levels of party unity on the floor by better structuring procedural votes.