Bonica, Adam, and Maya Sen. “The Politics of Selecting the Bench from the Bar: The Legal Profession and Partisan Incentives to Politicize the Judiciary.” HKS Faculty Research Working Paper Series RWP15-001, January 2015.

“The American judiciary has increasingly come under attack as polarized and politicized. Using a newly collected dataset that captures the ideological positioning of nearly half a million judges and lawyers who have made campaign contributions, we present empirical evidence showing politicization through various tiers of the judicial hierarchy. We show that the higher the court, the more conservative and more polarized it becomes, in contrast with the broader population of attorneys, who tend to be liberal. These findings suggest that political actors not only appear to rely on ideology in the selection of judges, but that they strategically prioritize higher courts. To our knowledge, our study is the first to provide a direct ideological comparison across tiers of the judiciary and between judges and lawyers, and also the first to document how—and why—American courts are politicized.”