How important is political ideology to the way judges decide cases? Are judges merely “politicians in robes,” or are they faithfully interpreting and applying the law? Political scientists have long been interested in these questions. We’re interested too, but we’re asking—and answering—these questions in a different way.
The first difference is our focus. The US Supreme Court has gotten the vast majority of the attention from researchers. In some ways, that makes sense. Supreme Court justices are the most public facing judges in the US, and their decisions can have wide-reaching consequences. But the Supreme Court consists of only nine justices deciding fewer than 100 cases per year. If we want to understand the role of politics in the US legal system, we cannot ignore the work-horses of the federal judiciary: the judges of the US District Courts (“district judges”). These 1000+ judges are assigned more than a quarter of a million civil and criminal cases per year.
A second difference is our data. To the extent that district judges have been the subject of study, much of the focus has been on cases in which a presiding judge wrote an opinion. But there is so much more happening in district courts. For example, one of the most common outcomes in district courts is a negotiated settlement between the plaintiff(s) and defendant(s). Settled cases frequently contain no written opinion from a judge. Indeed, the presiding judge may not have taken a single action before a case was settled. But the presiding judge may still have caused the settlement. Attorneys make great efforts to anticipate how a judge would rule on their case, and some judges have reputations for being more or less friendly to plaintiffs. For example, if a case is assigned to a judge with a plaintiff-friendly reputation, defense attorneys might be more willing to settle the case. If we ignore settlements, we would miss these important effects and maybe even draw mistaken conclusions about the impact of politics in district courts.
Our study avoids this problem. Over the course of multiple years, we collected over a million court records that allowed us to assemble a dataset of every single civil rights case heard in seven district courts from 1995 to 2016. With this dataset, we are able to see how every case assigned to every judge in these district courts ended, even if there was no opinion written. It allows us to get a fuller—and unbiased—picture of the extent to which it matters whether Democratic-appointed judges or Republican-appointed judges are assigned to hear civil rights cases.
Even with our novel dataset, it is still possible that Democratic-appointees and Republican-appointees hear different kinds of cases. If so, then we can’t necessarily conclude any differences we see between Democratic-appointees and Republican-appointees are genuine. Fortunately, we know that the cases assigned to Democratic-appointees and Republican-appointees are very similar (on average) because cases are randomly assigned to judges in federal courts. With some technical caveats we discuss in the paper, this allows us to approximate a randomized control trial (RCT), allowing for rigorous study of cause and effect.
This reveals a third difference with prior research. Many existing studies focus attention on how a judge’s political ideology affects their decision-making. Unfortunately, our approximated RCT does not allow us to answer that question. The RCT we described only allows us to hold constant the features of cases assigned to Democratic- and Republican-appointees. But to cleanly measure the effect of a judge’s political ideology on their decision-making, one would need to hold constant all features of judges except for their political ideologies. While many prior studies try to control for some things in their statistical analyses, like judges’ races and genders, it’s possible that Democratic- and Republican-appointees differ in other unmeasured ways, like their judicial temperaments, previous legal experiences, etc. The potential list is endless, so there’s little hope of ever isolating the true effect of political ideology. And once we start trying to isolate this effect, it becomes increasingly clear that it’s hard to even conceptualize what “the effect of political ideology” actually means.
Instead, we focus scholarly attention on a vitally important question that is much closer to what we can rigorously study: “what is the effect on civil rights cases when a Republican president, rather than a Democratic president, appoints federal district judges?” If we want to understand the stakes of presidential elections for civil rights outcomes in the federal courts, we needn’t concern ourselves with the impossible task of isolating the effect of judges’ political ideologies on their decision-making. We can get insights by instead simply examining how civil rights cases get resolved differently when assigned to Republican-appointees instead of Democratic-appointees.
We find that Republican-appointees cause fewer settlements and more dismissals in civil rights cases, favoring defendants by around 5 percentage points. We show that this is similar to the difference between Republican- and Democratic-appointees in the US Courts of Appeals for the Ninth Circuit, challenging the prevailing view that politics matters more in the circuit courts than in the district courts. When we look across three different time periods, we see the difference has been increasing: between 1995-2000 there was very little difference between Democratic- and Republican-appointees (about 1 percentage point). However, between 2001 and 2008 the difference grew to about five percentage points, and between 2009 and 2016, it grew further to about seven percentage points. A rough, back-of-the-envelope calculation based on our findings suggests that somewhere between 6,750 and 9,990 civil rights cases will end up favoring defendants (instead of plaintiffs) due to Donald Trump’s victory over Hillary Clinton in 2016.
All in all, we argue that our analysis provides strong evidence that politics matters quite a bit in district courts—at least in civil rights cases—but that scholars will have to study these courts differently than they have done in the past. We are excited to see the research on these important courts evolve in the coming years.
This blog piece is based on the article “Political Appointments and Outcomes in Federal District Courts” by Ryan Hubert and Ryan Copus, forthcoming in the Journal of Politics, April 2022.
The empirical analysis of this study has been successfully replicated by the Journal of Politics. Data replication materials are available at The Journal of Politics Dataverse.
About the Authors
Ryan Hübert – University of California, Davis
Ryan Hübert is an Assistant Professor of Political Science at the University of California, Davis. His research uses game theory and quantitative methods to study political institutions and the behavior of government officials. His substantive interests include American courts and policing, identity and discrimination, corruption and special interest influence on politics. You can find further information regarding his research here and follow him on Twitter: @ryan_hubert
Ryan Copus – University of Missouri-Kansas City School of Law
Ryan Copus is an Associate Professor at the University of Missouri–Kansas City School of Law. His research focuses on technically and ethically responsible ways to apply the power of machine learning to the study, evaluation, and regulation of legal decision-making. You can find further information regarding his research here and follow him on Twitter: @CopusRyan