Elections and Partisan Behavior in the U.S. Senate

Abstract

Senate elections affect senators’ partisan behavior. Senators encounter incentives to display party loyalty, but they must win reelection every six years to continue pursuing ideological, partisan, and career-based goals in the U.S. Senate. Since most senators desire reelection, they respond to credible electoral threats. Therefore, a senator’s electoral vulnerability affects his party loyalty. In this thesis, I examine the effect of elections on senators’ party loyalty through interviews with Senate staffers, analysis of senators’ roll-call voting, and studies of four senators’ careers. I conclude that senators facing competitive elections display less party loyalty toward the end of their terms relative to their colleagues. I also find that the effect of elections on senators’ party loyalty during the last two years of a Senate term parallel the effect of elections on the party loyalty on House incumbents seeking reelection. Overall, senators’ perceptions of electoral vulnerability influence how they represent their constituents.