Redistricting Institutions, Partisan Tides, and Congressional Competition

Abstract: The paper uses a simulation model and empirical evidence from four decades of congressional elections to generate insight into how redistricting institutions influence congressional seat competition under uncertain electoral conditions. The electoral model, which incorporates gerrymandering and partisan tides parameters, predicts that partisan gerrymanders will “backfire ” when partisan tides are sufficiently strong, and predicts increased competition for all electoral conditions under nonpartisan commissions. Drawing evidence from a data set of congressional election results since 1972, I find support for these predictions. I also use these results to explain the “pseudo-paradox ” that less competition in the national congressional popular vote historically predicts greater competition in individual local races