The Constituency Motivations of Caucus Membership

The popularity of congressional caucuses is puzzling, given the dominance of political parties and rules that specifically limit caucuses ’ resources. Yet modern caucuses offer legislators the unique advantage of complete discretion over their membership decisions, which allows legislators to tailor their memberships to their district. As a result, caucus membership is an important means of constituency representation. Using original data from the 108th Congress, this article examines the House caucus system and legislators ’ membership in all 441caucuses. There is strong evidence that legislators ’ decisions about cau-cus membership reflect their constituents even when controlling for party, committee, electoral security, and seniority. Legislators from heterogeneous districts belong to numerous caucuses, which allows them to represent the multiple interests in their constituency. In addition, legislators are more likely to belong to caucuses that address specific issues relevant to constituents