A Wisconsin judge ordered on December 13 that the registration of up to 234,000 voters be tossed out because they may have moved, a victory for conservatives that could make it more difficult for people to vote next year in the key swing state.

The judge sided with three voters represented by a conservative law firm who argued the state elections commission should have immediately deactivated any of the roughly 234,000 voters who didn’t respond to an October mailing within 30 days. The voters were flagged as having potentially moved.

Ozaukee County Judge Paul Malloy denied a request by elections commission attorneys to put his decision on hold. He ordered the state Elections Commission to follow the law requiring voters who didn’t respond to be deactivated.

“I can’t tell them how to do that, they’re going to have to figure that out,” Malloy said of the commission deactivating the voters.

Commission spokesman Reid Magney said that staff will analyze the judge’s decision and consult with commission members on next steps. The judge’s ruling comes in the early stages of the case and is expected to be immediately appealed. It is likely to ultimately go to the Wisconsin Supreme Court, which is controlled 5-2 by conservatives.

The case is important for both sides ahead of the 2020 presidential race in narrowly divided Wisconsin, which President Donald Trump won by fewer than 23,000 votes in 2016. Liberals fear the voters who could be purged are more likely to be Democrats. Republicans argue allowing them to remain on the rolls increases the risk of voter fraud.

The state elections commission, which has an equal number of Republicans and Democrats, is fighting the lawsuit. It argues that the law gives it the power to decide how to manage the voter registration list. It wants to wait until after the April 2021 election before removing anyone, citing concerns that everyone identified may not have moved and removing them would create confusion.

The commission also argued that leaving a registered voter on the polls, even if they have moved, does not mean they will actually commit fraud by voting at their old address. The elections commission decided to wait longer than 30 days to deactivate voters because of problems in 2017 after about 343,000 voters were flagged as potential movers. More than 300,000 people who did not respond were deactivated, leading to confusion, anger, and complaints.

Wisconsin allows same-day voter registration, but it requires photo ID and proof of address. The judge said Wisconsin law clearly required the elections commission to deactivate voters who did not respond to the mailing within 30 days. The commission had no basis to set a different time frame, he said.

“I don’t want to see anybody deactivated, but I don’t write the legislation,” Malloy said. “If you don’t like it, then I guess you have to go back to the Legislature. They didn’t do that.”

Karla Keckhaver, an assistant attorney general defending the commission, argued that not putting the ruling on hold pending appeal would create irreparable harm. “This would create chaos to do this now,” she said, referring to upcoming elections in February.

Some of the highest percentages of voters who could be tossed would be in Wisconsin’s two largest cities and areas with college campuses, epicenters of Democratic support. Milwaukee and Madison, the largest cities and base of Democratic support, account for 23% of the letters that were sent to voters who may have moved. More than half of the letters went to voters in municipalities where Democrat Hillary Clinton defeated Trump in 2016.

As of December 5, only about 16,500 of those who received the mailing had registered at their new address. More than 170,000 hadn’t responded, and the postal service was unable to deliver notifications to nearly 60,000 voters. While the lawsuit is pending, the commission has asked the Republican-controlled Legislature to provide clarity by passing a law or empowering the commission to create procedures on how to deal with voters who have moved.

Wisconsin has about 3.3 million registered voters out of about 4.5 million people of voting age. Next year’s presidential race is not the only high-stakes election that could be affected by the registration lawsuit. Wisconsin has a February primary for a seat on the highly partisan state Supreme Court. The state’s presidential primary is in April.

A day later on December 14, Pro-democracy advocates vowed to ensure all Wisconsin voters would be permitted to vote in the 2020 election. Ben Wikler, chair of the Wisconsin Democratic Party, called the purge a “product of a right-wing legal and political strategy to prevent eligible voters from voting.”

“It should be a concern to anyone who believes in the core idea of democracy,” said Wikler. “Now our job is to organize harder than they can suppress.”

He noted on Twitter that voters whose names are removed from rolls can still re-register in the state, including on Election Day. He called on voting rights advocates to help make sure purged voters get to the polls in 2020. The League of Women Voters and election officials said they would fight the judge’s decision in court.

“I won the race for governor by less than 30,000 votes. This move pushed by Republicans to remove 200,000 Wisconsinites from the voter rolls is just another attempt at overriding the will of the people and stifling the democratic process.” – Governor Tony Evers

Former Attorney General Eric Holder said the right-wing effort to create confusion among likely-Democratic voters in a state where President Donald Trump won by less than 23,000 votes in 2016 was “expected unfairness” from the conservative group.

“Here they go. Voter purge in Wisconsin that disproportionately targets Democrats, people of color and those who voted for Hillary in 2016. The expected unfairness. Fight this Wisconsin! Fight for a fair election.” – Eric Holder