Just 33 minutes after polls closed in the primary election for a Wisconsin Supreme Court seat that will determine the balance of power on one of the most powerful and contentious judicial benches in the country, the Associated Press announced that liberal candidate Janet Protasiewicz will advance to the general election on April 4. The Milwaukee County judge, who ran as an unapologetic defender of abortion rights and fair elections, overwhelmed the other three contenders in the first round of a contest that political observers on both sides of the nation’s partisan divide consider the most consequential election fight of 2023.

The Wisconsin court currently has a 4-3 conservative majority. But if Protasiewicz wins the seat that is being vacated by a conservative justice, the court will flip to a 4-3 liberal majority. That majority would be positioned to reject an 1849 Wisconsin law that effectively bans access to abortion in the state. It could overturn many of the assaults on labor rights initiated by Republican former Governor Scott Walker. And it will have the power to upend gerrymandered state legislative and congressional maps that gave Republicans an unfair advantage in elections over the past decade.

“I think we have exceeded all of our expectations, haven’t we?” Protasiewicz told cheering supporters Tuesday night in Milwaukee.

That she did.

With almost all of the votes counted in the high-stakes primary election, Protasiewicz was winning 46.4 percent to 24.2 percent for former Supreme Court justice Dan Kelly, a hard-core conservative who was defeated by more than 150,000 votes when he sought a full term on the high court in 2020.

Another conservative, Waukesha County Judge Jennifer Dorow, won 21.9 percent of the vote on Tuesday, while liberal Dane County Judge Everett Mitchell took 7.5 percent.

What that means is that the combined liberal vote in the primary was roughly 54 percent, while the combined conservative vote was 46 percent. That’s encouraging news for Protasiewicz, a prodigious fundraiser who has received strong endorsements from unions, progressive groups, and, with her primary win, the Democratic Party of Wisconsin. She’s also backed by the three liberals on the current court, including Justice Jill Karofsky, who had sat out the race until this week. Karofsky, who beat Kelly in a high-stakes 2020 race, made her endorsement of Protasiewicz on Tuesday night, saying, “Wisconsinites need a Supreme Court justice who will always uphold the constitution, rather than promote a right-wing political agenda. Judge Janet Protasiewicz will be an independent justice—and deliver on the promise of justice—and I’m proud to support her in this race.”

With all of this said, the April 4 election will still be highly competitive, and highly expensive. Analysts are predicting that the Wisconsin race will be the costliest state supreme court contest in US history. That’s a measure of what’s at stake in a contest that will provide voters, many of whom will have to overcome voter-suppression tactics to even cast their ballots in the election, with a stark choice in the historic battleground state.

Kelly, who was appointed to a high court vacancy by former Governor Walker and who unsuccessfully sought a full term in 2020 with the support of former President Donald Trump, went on to do legal work for state and national Republican Party groups during the 2020 wrangling over Wisconsin presidential election results. This year, he ran as an aggressive conservative whose supporters aired television ads promising to block “a liberal takeover” of the Supreme Court.

Protasiewicz promised to frame the race with Kelly as a test of values. “I value a woman’s freedom to make her own health care decisions. I value our democracy. And I believe that every Wisconsinite deserves to be fairly represented,” the candidate told her supporters on Tuesday night. “Everything we care about is going to be determined by who wins this election.”