Voters in Wisconsin will likely face a choice on Tuesday of participating in a presidential primary election or heeding warnings from public health officials to stay away from large crowds during the coronavirus pandemic.

The Wisconsin Supreme Court on Monday ordered the election back on, hours after Democratic Gov. Tony Evers issued an executive order postponing it for two months. That was part of a last-ditch effort by Evers to stop in-person voting on Tuesday out of concerns about putting poll workers and voters at risk of being exposed to COVID-19.

The court ruled 4-2, with four conservatives in support and two liberals against, that Evers lacked the authority to move the election on his own. Evers had previously opposed moving the election and said he didn’t have the authority to shift the timing unilaterally. But he changed course Monday, ordering a delay of in-person voting to June 9, as poll sites closed because nervous volunteers were unwilling to staff them and as criticism about holding the election grew.

The governor said his order was the last hope for stopping the election, and he had no immediate comment after the ruling about any other possible legal challenges.

“There’s not a Plan B. There’s not a Plan C,” Evers said earlier Monday.

The Wisconsin election is being viewed as a national test case in a broader fight over voter access in the age of the coronavirus with major implications for the presidential primary contests ahead — and, possibly, the November general election. Many other states pushed their primaries back as the coronavirus swept across the nation.

Later Monday, the U.S. Supreme Court blocked a plan to extend absentee voting in Wisconsin’s spring primary by six days because of the coronavirus. Republicans had asked the court to throw out a lower court’s order extending absentee voting to April 13. The justices split 5-4, with the five Republican-appointed justices siding with national and Wisconsin Republicans to prohibit the expanded absentee voting.

At the presidential level, Joe Biden already has a commanding delegate lead over Bernie Sanders, and the Wisconsin results aren’t likely to dampen his march to the Democratic nomination. But the tumult in one of the most critical general election battlegrounds underscored the challenge of voting during a pandemic when public health officials are discouraging groups from gathering for virtually any reason to prevent the spread of the virus.

Evers himself had questioned whether he had the power to reschedule the election, but said the worsening situation, including an increase in COVID-19 deaths from 56 on Friday to 77 on Monday, made it clear there was no way to safely move forward. Evers said he was motivated by protecting public health, not politics.

“The people of Wisconsin, the majority of them, don’t spend all their waking hours thinking about are Republicans or Democrats getting the upper hand here,” Evers said earlier Monday. “They’re saying they’re scared. They’re scared of going to the polls.”

Evers and Republicans initially agreed that it was imperative for the election to proceed because thousands of local offices are on the ballot Tuesday for terms that begin in two weeks. There is also a state Supreme Court election.

Ohio saw a similar eleventh-hour flurry the day before its primary last month. After the governor and secretary of state failed to persuade a judge to shift the election date, the state health director stepped in and ordered voting shut down. Legislators set a new, almost all-mail primary for April 28, sparking new legal challenges from voting rights groups, but a federal judge on Friday said the election could go forward.

Wisconsin Democratic state Sen. Jon Erpenbach said Republicans want to suppress turnout, particularly in Democrat-heavy Milwaukee, because that will benefit Republicans.

“Democrats have always been good about getting out the vote on the day of,” Erpenbach said. “If you’re looking at the newspapers, watching TV, you know right now it’s dangerous.”

Evers is among the governors who have issued a stay-at-home order and closed all nonessential businesses.

“Your choice is to go and vote in person and take a chance on contracting COVID-19 or stay home,” Erpenbach said. “What do you think people are going to do?”

The state and national Democratic parties, along with a host of other liberal and voter advocacy groups, filed federal lawsuits seeking a delay in the election and other changes. A federal court judge just last week handed Democrats a partial win, allowing for absentee ballots to be counted through April 13, delaying the reporting of election results until then. But the judge, and later a federal appeals court, declined to postpone the election.

Republicans appealed to the U.S. Supreme Court, asking that it not allow absentee ballots to be counted beyond Tuesday because partial results could be leaked. The top court ruled in their favor late Monday.

Democrats feared the move would disenfranchise thousands of voters.

Thousands of poll workers had said they wouldn’t work, leading Milwaukee to reduce its planned number of polling sites from 180 to just five. More than 2,500 National Guard troops were dispatched to staff the polls. They were also distributing supplies, including hand sanitizer, to polling sites across the state. In Madison, city workers were erecting plexiglass barriers to protect poll workers, and voters were encouraged to bring their own pens to mark the ballots.

George Dunst, 76, of Madison, who has volunteered at his local polling site for nearly every election since he retired, said he’s not going Tuesday amid fears of contracting COVID-19.

“No matter what safety precautions you take, there’s going to be exposure,” he said. “Who knows who comes into the polling place?”

More coronavirus coverage from Fortune:

—New York City prepares to use parks as temporary burial sites
—Millions won’t be able to pay their bills this month. What financial experts advise
—What small businesses applying to the SBA’s Paycheck Protection Program need to know
—What’s going to happen to your frequent-flier status and miles
—Why the U.S. is changing its mind on coronavirus face masks
—JP Morgan’s Jamie Dimon lays out a future worse than 2008 in his annual letter
—Coronavirus upends learning and cancels spring tests for millions of U.S. students
—PODCAST: Two health care CEOs on why coronavirus tests and vaccines are the ammunition needed to fight COVID-19
—VIDEO: 401(k) withdrawal penalties waived for anyone hurt by COVID-19