Procedural Polarization in the U.S. Congress

Abstract

This article examines party polarization in Congress. It finds that almost the entire growth in party polarization since the early 1970s can be explained by the increased frequency of and polarization on procedural votes in the both the House and the Senate. This finding answers several questions about party polarization, but asks one new questions that it only begins to answer: what are procedural votes? Preliminary analysis suggests that members of Congress view procedural votes as separate and distinct from substantive votes. On the former, their party has a substantial influence on their behavior and on the latter, their constituency has a substantial influence.