The Influence of Law and Partisanship on Redistricting Decisions in the Federal Courts

Much research has been devoted to the electoral or policy effects of redistricting as well as the normative implications of court involvement. However, few systematic studies of judges' behavior in redistricting exist. Redistricting cases offer a unique opportunity to test the effects of partisan affect, as distinct from ideology, in federal judges' decision making. In an analysis of federal district court cases from 1981 to 2007, this paper examines the influence of partisanship and the law on judicial decisions in redistricting and finds that federal judges neither act as neutral arbiters nor crass partisans. Instead, judging in these cases can best be described in terms of constrained partisanship. When redistricting law is unambiguous, as is the case in equal population jurisprudence, partisanship has no effect on decision making while the law has a strong constraining influence. However, where redistricting law is murkier, partisanship has a pronounced effect on judicial behavior.