I have just uploaded to SSRN a draft of a forthcoming article I have coauthored with Kevin Quinn and ByungKoo Kim entitled Twenty-First Century Split: Partisan, Racial, and Gender Differences in Circuit Judges Following Earlier Opinions. We have not started the editing process, so we would love to read any comments you might have. Here is a summary of the article (the abstract plus a bit more):
Judges shape the law with their votes and the reasoning in their opinions. An important element of the latter is which opinions they follow, and thus elevate, and which they cast doubt on, and thus diminish. Using a unique and comprehensive dataset containing the substantive Shepard’s treatments of all circuit court published and unpublished opinions issued between 1974 and 2017, we examine the relationship between judges’ substantive treatments of earlier appellate opinions and their party, race, and gender. Are judges of a particular party, race, or gender more likely to positively treat (that is, follow) opinions written by judges who share that attribute than are judges of a different party, race, or gender? What we find is both surprising and nuanced. We have two major findings.
First, over the forty-four years of our study, we find growing partisan differences in positive treatments of earlier opinions. The partisan differences are largest for treatments in ideologically salient categories of cases. Interestingly, the partisan differences arise more for treatments of opinions written by Democratic appointees than for opinions written by Republican appointees, which we think is best explained by an accelerating movement among Republican appointees in a conservative direction compared to a steady move among Democratic appointees in a liberal direction. The increase in partisan differences is not a function of presidential cohorts or age cohorts. More recently appointed judges and judges appointed decades ago show similar patterns of increasing partisan differences in recent years. And this is not a function of less partisan judges retiring earlier: the recent partisan differences apply when we focus only on judges who served during the same extended period of time.
Second, there are intra-party racial and gender differences in positive treatments of past opinions, and these differences are similar to the partisan differences. Within each party, Black and White judges differ in their treatments of opinions authored by Black copartisans, Hispanic and White judges differ in their treatments of opinions authored by Hispanic copartisans, and female and male judges differ in their treatments of opinions authored by female copartisans. Similar to the partisan divergence noted above, we also find that some of these differences increase in magnitude over time—with particularly notable increases in the Black-White Democratic differences, Hispanic-White Republican differences, and female-male Republican differences. Notably, the racial and gender differences we find in positive Shepard’s treatments are not mirrored in most studies of racial and gender differences in judicial behavior, which focus on merits votes and include a much smaller number of cases.
These results defy easy explanation. They do not support the proposition that party, race, and gender have always played a pervasive role for judges. Instead, our results provide evidence of increasing partisan, racial, and gender polarization among judges in recent years. For reasons we explain in the article, the partisan, racial, and gender differences we find appear to be a function of political ideology. Further, because the racial and gender differences are within parties, our results indicate that not only partisan differences but also intra-party racial and gender ideological differences have risen in recent years (particularly for Republican judges).
Our data thus reveal polarization among circuit judges and, as a result, in their shaping of the law. Many groups in the United States have become more ideologically polarized in recent years. Our data indicate that judges are one of them.