Wisconsin Supreme Court Justice Pat Roggensack is trying to beat back a challenge from Marquette University law professor Ed Fallone in the race for a 10-year term.
In the other statewide contest Tuesday, state superintendent Tony Evers is vying for a second four-year term against Republican state Rep. Don Pridemore.
They are the only two statewide races on the ballot. Turnout is expected to be about 20 percent.
Fallone argues Roggensack needs to be replaced because the Supreme Court is dysfunctional and catering to special interests. But Roggensack outraised Fallone and has had conservative outside groups run television ads on her behalf.
Evers has the backing of several Democratic officeholders and unions, including the one representing teachers. Evers has outraised Pridemore, who did not run any television ads.