From Gridlock to Polarization

We propose a mechanism linking legislative gridlock to voters’ support for candidates who hold extreme policy positions. Moderate voters rationally discount extreme pol- icy proposals from co-partisans on gridlocked policy issues because on these issues policy change is unlikely. We test our mechanism in a large-scale online experiment in which we randomly vary subjects’ perceptions of gridlock and measure subjects’ support for co-partisan candidates in candidate-choice tasks. We verify that greater perception of gridlock increases moderate subjects’ propensity to vote for extreme co- partisan candidates. We show that our experimental evidence is consistent with our mechanism and that other mechanisms are less likely to underlie our main result. Our theory offers a causal connection from gridlock to elite polarization that may inform further empirical work and suggests a novel tradeoff between elite polarization and policy stability in constitutional design