As redistricting efforts are underway across the county, state courts are hearing challenges to new voting maps. An Alaska state court will hear a challenge to that state’s redistricting map on May 3. A New York judge delayed the state’s congressional and state Senate primaries after the state’s highest court struck down that state’s latest map, seen as favoring Democrats. The Ohio Supreme Court has given the state legislature a May 6 deadline to fix its latest map — the fourth submitted so far, all rejected for partisan bias.
Democrats have been particularly active in using courts to challenge redistricting maps, and have succeeded often enough that some Republicans have nicknamed the strategy “sue until blue.”
Those lawsuits have had an unintended consequence: Elections for state supreme court judges have become more politicized, as political parties assume that redistricting votes will be swayed by loyalty to the party. In states where judges are elected, parties have been organizing around efforts to “flip” the partisan composition of state supreme courts. In the 2019-2020 election cycle alone, parties spent upward of $97 million on judicial elections, according to a report by the Brennan Center for Justice, a research and advocacy group on voting and civil rights.
Of course, judges don’t always support their party. In Ohio, for instance, the state supreme court’s Republican chief justice, Maureen O’Connor, voted against Republican-drawn district maps, a decision denounced by state Republican leaders. Similarly, conservative Wisconsin Supreme Court Justice Brian Hagedorn recently voted against a Republican-drawn map there. Still, research has shown that in cases where the political parties will be affected, judges can be influenced by partisanship, even when judges are appointed.
Is it true that state supreme court votes in redistricting fights are influenced by party loyalty? My colleagues and I have found that the answer is yes — especially when Republican plans are challenged for partisan bias.
How we did our research
To understand whether state supreme court judges are — on average — influenced by party loyalty on redistricting cases, we collected data on votes on redistricting cases in all states from 1961 to 2022. We also collected data on the party affiliation of the judges who voted in these cases. Our data include both elected and appointed judges. If judges were not elected, we obtained party affiliation from judicial websites, biographical data and media searches.
We analyzed votes across all redistricting litigation cases, and paid particular attention to cases that alleged partisan gerrymandering, where maps are allegedly skewed to favor one party over another. We examined party loyalty in all judges, but considered voting differences between Democratic and Republican judges, too. We also considered whether any of this varied by how judges were chosen to be in their position: in partisan or nonpartisan elections, by a governor’s appointment, or by nominating commission.
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Judges are somewhat more likely to decide in favor of their party
We found that state supreme court judges vote to uphold redistricting plans approximately 66 percent of the time. Much of the time, courts are unanimous.
However, when courts are divided, judges who belong to the same party as the legislative majority are slightly more likely to uphold redistricting plans than judges who belong to the opposition party. When cases aren’t unanimous, a majority-party judge has a 53 percent likelihood of upholding a redistricting plan while an opposition-party judge has a 47 percent likelihood.
When the redistricting challenge alleges that the map was gerrymandered to advantage one party, we found larger differences. Majority-party judges have a 58 percent likelihood that they will uphold such plans, while opposition judges have only a 50 percent likelihood.
When we examine differences between Republican and Democratic judges, the biggest differences in their voting behavior occurs when Republican redistricting plans are challenged. When a Republican-majority plan is challenged, a Republican judge has a 20 percent greater likelihood of supporting that plan than a Democratic judge. However, when the lawsuit against the Republican plan alleges partisan bias, the difference is even greater. In these cases, a Republican judge has a 338 percent greater likelihood of upholding the plan than a Democratic judge — or to put it differently, they are nearly 3½ times more likely to uphold their party’s map, just as a Democratic judge is that likely to vote against it.
How judges are selected affects their decisions, too
How a judge is chosen also appears to influence whether party loyalty impacts their votes on redistricting cases. Judges selected using a nominating commission show more evidence of party loyalty voting in redistricting cases. Meanwhile, judges appointed by governors and elected in partisan elections are somewhat likely to vote with their party on such cases. Finally, judges in the 13 states chosen by nonpartisan elections show no signs of supporting a redistricting plan just because it comes from their party.
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Judges do vote with party in mind
Our research shows that, where redistricting is concerned, parties can benefit from state supreme courts made up of judges from their own party, especially when redistricting challenges are based on claims of partisan gerrymandering. Of course, not all judges demonstrate the same willingness to support their party. A lesson here for parties is that they can be strategic in using resources to get judges on state supreme courts, and will probably see a positive result for their efforts. A lesson here for citizens who are concerned about judges being partisan in their legal decisions is that selecting them by nonpartisan elections seems to offer the most “protection” from that.
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Teena Wilhelm is an associate professor in the department of political science in the School of Public and International Affairs at the University of Georgia.