Measuring Ideological Polarization on the Circuit Courts of Appeals 1953-2022

Abstract Attention to ideological polarization in the Circuit Courts of Appeals has surged in recent years. However, no valid cross-circuit cardinal measure of polarization has been established. The lack of a valid cross-circuit measure of polarization has limited scholar’s ability to evaluate broad trends in judicial polarization and address how ideological polarization influences judicial decision-making. To address this, I develop a new measure of ideological polarization for each of the Circuit Courts of Appeals between 1953 and 2022 using the polarization framework established by Esteban and Ray (1994). I then theorize that in order to uphold the norms of collegiality, more polarized courts are likely to take strategic actions to avoid breaking consensus. I show that polarized courts deliberate longer before releasing opinions, are less likely to give cases with a full hearing, and are less likely to publish justified and signed opinions. These results have implications for the efficiency, efficacy, and authority of the Circuit Courts of Appeals.