The partisan makeup of two of the country’s most politically divided state supreme courts changed as a result of the 2020 elections, according to a Ballotpedia ranking of states by supreme court partisanship.
As part of the Ballotpedia Courts: State Partisanship study, Ballotpedia assigned each state supreme court justice a partisan confidence score based on factors including the justice’s history of political contributions and personal political party membership. Each individual justice’s confidence score was considered when assessing how divided a particular state’s supreme court was.
The primary factor in determining a court’s overall political homogeneity is whether the court is split or has a majority of one party. We also considered the difference between the low score and the high score of justices on the court, the ratio of justices with strong partisan Confidence Scores to justices with indeterminate Confidence Scores, and the ratio of justices with Democratic and Republican Confidence Scores on the court.
The states with the least homogeneous supreme courts—in other words, with the most partisan differences among justices—were Michigan, Illinois, New Jersey, Tennessee, and Vermont.
Illinois had the least homogeneous court with a Democratic majority; four justices had Democratic confidence scores and three had Republican confidence scores.
Michigan, Tennessee, and West Virginia had the least homogeneous courts with Republican majorities. Michigan had a 4-3 majority of justices with Republican confidence scores, while Tennessee had a 3-2 majority. West Virginia a 4-1 majority, although two of the Republican-aligned justices also had links to the Democratic Party.
The 2020 election changed the composition of both the Illinois and Michigan state supreme courts.
In Michigan, Justice Stephen Markman (R) had to retire due to the state’s mandatory retirement age and Chief Justice Bridget Mary McCormack (D) ran for reelection. Justice Markman was one of the four justices in the majority who recorded Republican Confidence Scores according to our study. Elizabeth Welch, who was one of the state Democratic Party’s two nominees, was the second-highest vote-getter and will take Markman’s seat. Justice McCormack was the highest vote-getter and will retain her seat on the court. As a result of this election, the Michigan Supreme Court went from a 4-3 majority of Republican-leaning justices to a 4-3 majority of Democratic-leaning justices.
In Illinois, Justice Thomas Kilbride (D) stood for retention election, where voters choose “yes” or “no” to retain a justice on the court. In Illinois, a justice must win at least 60% of the vote in order to win retention. Justice Kilbride received 56% of the vote and will vacate the seat as a result. In the interim, the Illinois Supreme Court will choose a justice to fill the vacancy of Kilbride’s seat for 2021. There will be an election to choose a justice to permanently fill Kilbride’s seat in 2022.