As the 2010 midterm election approaches, U.S. senators running for reelection
encounter conflicting partisan and electoral pressures. Those facing competitive
general elections appeal to swing voters by distancing themselves from their party.
Meanwhile, senators have strong incentives to demonstrate their party loyalty to
colleagues, party leaders, and their party’s electoral base. When senators vote,
they must balance these partisan and electoral considerations. I hypothesize that
senators facing competitive elections will be less likely to vote with their party than
This project examines the link between senators’ voting records and the
competitiveness of Senate elections from 1996 to 2008. Using elections data and
vote studies from Congressional Quarterly, I compare senators facing competitive
elections with senators defending safe seats. In addition, I analyze changes in
senators’ voting patterns over their six-year terms. My results help explain partisan
behavior in the U.S. Senate and provide insight into the upcoming election.