Wisconsin voters will choose between a Republican appointee, a Madison judge and a law professor as they winnow down the candidates for a state Supreme Court seat in a primary Tuesday.

Conservative Justice Dan Kelly will face off against liberal-leaning Jill Karofsky and Ed Fallone. The top two vote-getters will advance to the April 7 general election with a 10-year term on the high court at stake.

The race can’t change the court’s ideological leaning since conservative-leaning justices currently have a 5-2 edge. But a Kelly defeat would cut their margin to 4-3 and give liberals a shot at a majority in 2023.

Then-Gov. Scott Walker, a Republican, appointed Kelly to the Supreme Court in 2016 to replace the retiring David Prosser. An attorney by trade, he represented Republican lawmakers in a federal trial over whether they illegally gerrymandered Wisconsin’s legislative district boundaries in 2011. He’s also a member of The Federalist Society, a conservative organization that advocates for a strict interpretation of the U.S. Constitution.

Karofsky is a wiry marathon runner who has completed two Iron Man competitions. She also won the state doubles tennis championship in 1982 for Middleton High School.

She has served as an assistant prosecutor in the Dane County district attorney’s office, general counsel for the National Conference of Bar Examiners and executive director of the state Department of Justice’s Office of Crime Victim Services. She won election as a Dane County circuit judge in 2017.