Abstract

Intra-party factions have increasingly wielded influence on key agenda items in the U.S. Congress. To better understand the welfare implications of these groups, this paper presents a formal model in which incumbents choose to join a faction and cast a vote on the majority party’s agenda, after which an election takes place. This theory shows that while factions may enable incumbents to vote against the party’s agenda, factions can have positive effects on party welfare by signaling incumbents’ ideological type to their districts, thereby improving incumbents’ reelection prospects and increasing the number of seats held by the party. I present case studies on the House Freedom Caucus’s opposition to a funding measure for the DHS and the Blue Dog Democrats’ defections on cap-and-trade to illustrate the theory.