Look for the party label: Party influences on voting in the U.S. House

Since party is so highly correlated with ideology, party-line voting in the U.S. House may indicate members voting their own preferences. If, however, the reputation of a member's party is valuable as a cue for voters and other party supporters, then legislators should be willing to vote against their own preferences and for those of their party, at least sometimes. To investigate whether and how often this does occur, we use roll-call data from the House from the 1950s to 1990s to perform cross-sectional and other tests that isolate the effects of parties, including analyses of members who switch parties. Our regression results indicate that party influence on voting has varied, but that there is an effect, even when controlling for ideology.