Abstract
This study examines how partisanship and institutional design shape polarization on U.S. State Supreme Courts and Federal Courts of Appeal. While legislative bodies have long been the focus of polarization research, courts, especially those with contestable elections, are increasingly politicized, raising questions about whether similar partisan dynamics apply. We argue that electoral pressures are a key driver of judicial partisanship: judges facing competitive elections are incentivized to vote in line with their party to secure campaign resources, appeal to partisan voters, and build reputations for loyalty. In contrast, judges insulated from electoral threat may prioritize consensus and collegiality to preserve institutional legitimacy. Using an original dataset of state court decisions from 1953–2015 and federal appellate decisions from 1912–2020, the study measures party cohesion (the proportion of votes aligned with a judge’s party) and polarization (the ideological distance between party medians) via Bayesian IRT methods. These measures are paired with data on judicial selection mechanisms, court leadership, professionalization, and electoral competitiveness. We find that courts with partisan elections, high professionalization, and competitive environments exhibit greater polarization and party unity. However, institutional norms, such as consensus traditions and leadership structures, can moderate these effects. The study contributes to a deeper understanding of how institutional design and electoral incentives interact to shape judicial behavior, offering a nuanced view of polarization beyond legislatures and highlighting the complex role courts play in the broader political landscape.
Presenters
Jason WindettProfessor, Data Science/Political Science and Public Administration, University of North Carolina at Charlotte, North Carolina, United States
Details
Presentation Type
Paper Presentation in a Themed Session
Theme
KEYWORDS
Polarization, Judicial Behavior, State Politics, Federal Courts
