Thomsen, Danielle M. 2017. Opting Out of Congress: Partisan Polarization and the Decline of Moderate Candidates. New York: Cambridge University Press.

  • Scholars have focused on mass-level and institutional-level explanations for the rise in partisan polarization in the U.S. Congress.  My book instead examines ideological changes in the candidates who run for Congress.  The central argument is that moderates are opting out of the congressional candidate pool, further exacerbating the ideological gulf between the parties in Congress.  Liberal Republicans and conservative Democrats are outsiders in both parties, and the personal and professional benefits of congressional service are too low for them to run.  Although the political center has long been deemed a coveted position in the legislature, it is now an increasingly lonely and lowly place to be.  The focus on the supply of congressional candidates sheds light on why polarization has continued to grow unabated and why recent policy reforms have been largely ineffective to date.
  • Reviewed in Choice, Congress & the Presidency, The Forum, Perspectives on Politics, and Political Science Quarterly.
  • Featured in a Monkey Cage op-ed and on C-SPAN Book TV.


Thomsen, Danielle M. “Competition in Congressional Elections: Money versus Votes.” Forthcoming at the American Political Science Review.

Treul, Sarah, Danielle M. Thomsen, Craig Volden, and Alan E. Wiseman. “The Primary Path for Turning Legislative Effectiveness into Electoral Success.” Journal of Politics 84(3): 1714-1726.

Thomsen, Danielle M. and Aaron S. King. 2020. “Women’s Representation and the Gendered Pipeline to Power.” American Political Science Review 114(4): 989-1000.

Thomsen, Danielle M. and Bailey K. Sanders. 2020. “Gender Differences in Legislator Responsiveness.” Perspectives on Politics 18(4): 1017-1030.

Thomsen, Danielle M. 2020. “Ideology and Gender in U.S. House Elections.” Political Behavior 42(2): 415-442.

Thomsen, Danielle M. 2019. “Which Women Win? Partisan Changes in Victory Patterns in U.S. House Elections.” Politics, Groups, and Identities 7(2): 412-428.

Thomsen, Danielle. M. 2017. “Joining Patterns Across Party Factions in the U.S. Congress.” The Forum 15(4): 741-751.

Koch, Julianna and Danielle M. Thomsen. 2017. “Gender Equality Mood Across States and Over Time.” State Politics & Policy Quarterly 17(4): 351-360.

Thomsen, Danielle M. and Michele L. Swers. 2017. “Which Women Can Run? Gender, Partisanship, and Candidate Donor Networks.” Political Research Quarterly 70(2): 449-463.

Aldrich, John H. and Danielle M. Thomsen. 2017. “Party, Policy, and the Ambition to Run for Higher Office.” Legislative Studies Quarterly 42(2): 321-343.

Thomsen, Danielle M. 2015. “Why So Few (Republican) Women? Explaining the Partisan Imbalance of Women in the U.S. Congress.” Legislative Studies Quarterly 40(2): 295-323.

Thomsen, Danielle M. 2014. “Ideological Moderates Won’t Run: How Party Fit Matters for Partisan Polarization in Congress.” Journal of Politics 76(3): 786-797.

Work in Progress

Money as Muscle in American Elections. Book manuscript.

“Money and Candidate Exit in U.S. House Elections.” Under review.

“Gender Differences in Candidate Reemergence.” Paper presented at the annual meeting of the American Political Science Association.