How do federal judges in the lower courts and justices in state supreme courts decide highly political and polarizing redistricting disputes? This study develops a complex view of judicial behavior in redistricting. When the law is clear, lower court judges don&t show any partisan favoritism in their rulings. When the law is ambiguous, judges tend to favor their party in cases, especially when their party is the victim of partisan line drawing by the state. McKenzie shows that polarization has increased over time in opinions about redistricting by federal judges, but federal judges who were independents prior to coming to the bench tend to be immune to partisanship. No state supreme court system appears immune to at least some partisan behavior. Judges, Law and Partisanship details important implications for how we view courts in partisan political disputes and what reforms to the process are possible.