The Politics of Selecting the Bench from the Bar: The Legal Profession and Partisan Incentives to Introduce Ideology into Judicial Selection

Using a data set capturing the ideological positioning of nearly half a million US judges and lawyers, we present evidence showing how ideology affects the selection of judges across federal and state judiciaries. We document that the higher the court, the more it deviates ideologically from the ideology of attorneys, which suggests that ideology plays a strong role in judicial selection. We also show that ideology plays stronger roles in jurisdictions where judges are selected via political appointments or partisan elections. Our findings suggest that ideology is an important component of judicial selection primarily when using ideology leads to expected benefits to politicians, when the jurisdiction's selection process allows ideology to be used, and when it concerns the most important courts. This study is the first to provide a direct ideological comparison across judicial tiers and between judges and lawyers and to explain how and why American courts become politicized.