I have written this draft paper for the Annual Review of Political Science (forthcoming 2019). Here is the abstract:
The period of increased polarization in the United States among the political branches and citizenry affects the selection, work, perception, and relative power of state and federal judges, including Justices of the United States Supreme Court. Polarization in the United States over the last few decades matters to the American judicial system in at least four ways. First, polarization affects judicial selection, whether the selection method is (sometimes partisan-based) elections or appointment by political actors. In times of greater polarization, governors and presidents who nominate judges, legislators who confirm judges, and voters who vote on judicial candidates are more apt to support or oppose judges based upon partisan affiliation or cues. Second, and driven in part by selection mechanisms, polarization may be reflected in the decisions that judges make, especially on issues that divide people politically, such as abortion, guns, or affirmative action. On the Supreme Court, for example, the Court often divides along party and ideological lines in votes in the most prominent and highly contested cases. Those ideological lines now overlap with party as we enter a period in which all the Court liberals have been appointed by Democratic Presidents and all the Court conservatives have been appointed by Republican Presidents. Third, increasingly polarized judicial decisions appear to be causing the public to view judges and judicial decision-making though a more partisan lens, at least when considering public attitudes about the United States Supreme Court. Fourth, polarization may affect the separation of powers, by empowering courts against polarized legislative bodies which sometimes cannot act thanks to legislative gridlock. The Article concludes by considering how increased polarization may interact with the judiciary and judicial branch going forward and suggesting areas for future research.
And here is one of the figures from the paper: