MILWAUKEE — Wisconsin voters headed to the polls in large numbers for the start of early voting Tuesday amid a spike in coronavirus cases that has turned the state into one of the country’s latest pandemic hot spots.

People began showing up at polling sites before sunrise, forming lines that stretched a block or more in some places. Pandemic precautions were on full display: Voters and election officials donned masks, workers wiped down booths with disinfectant, and those waiting kept roughly six feet apart as the lines crept forward.

Wisconsin, where mail-in ballots started going out in mid-September, has already exceeded the total number of early votes cast in 2016, according to a tracker by The Washington Post. Nationwide, more than 33 million people have voted early, at least 17 million of them in battleground states.

Outside a downtown polling site here in Milwaukee, 68-year-old Angie Ramsey waited in a line of about 80 people to cast a vote for Joe Biden, the Democratic nominee. These days, with the pandemic raging, she rarely leaves the house, she said.

“I go out to grocery shop on Fridays, and to vote,” Ramsey said. “Otherwise, I’m home.”

The growing wave of coronavirus cases that has swept across the country in recent weeks has hit Wisconsin especially hard, prompting election officials to double down on protective measures that they first implemented during primaries and local elections held in the early stages of the pandemic, when cases were less widespread.

Wisconsin’s rolling average for daily infections has risen sharply since the end of the summer, climbing from fewer than 1,000 in early September to more than 3,000 now. The state is regularly setting records for new cases in a single day, topping 4,000 twice last week.

In the past week, new daily reported cases have jumped more than 20 percent, hospitalizations have risen more than 26 percent, and daily reported deaths have increased 22 percent, according to The Post’s analysis of state health data.

More tests are being administered in the state, according to The Post’s tracking, but the positivity rate has remained above 12 percent, far higher than what experts say is necessary to control the spread of infections. Wisconsin ranks fourth among U.S. states in daily reported cases per capita, with 59 per 100,000 residents.

So far, the rising case numbers don’t appear to be discouraging voters, who streamed in by the dozens at polls across the state Tuesday.

“They’re undeterred. They’re going to vote,” said Scott McDonell, the county clerk in Dane County, which encompasses Madison. “I expect record turnout."

Twenty miles west of Milwaukee, a line of voters, all of them masked and distanced, waited outside city hall in Waukesha, a Republican stronghold.

“I just thought it was a good idea to get it over with,” said Robert Pettis, 84. He said he has voted in every election since he was 20, but had never voted early before, other than casting an absentee ballot during military service in Germany.

He arrived at city hall at about 8 a.m. and was encouraged by the line of voters that spilled far down the sidewalk outside the under-construction building.

“I was hoping that there would be a line,” he said, indicating that it showed enthusiasm. “It went real good.”

With 10 electoral votes, Wisconsin is one of a few potential tipping-point states in the presidential election. A Washington Post average of polls in the state shows Biden leading there by eight points.

While some states allow election officials to start tabulating early votes and mail-in ballots before Election Day, Wisconsin bars the practice. Local clerks have pleaded with the state legislature to pass a law allowing them to get a head start, and the state’s senior senator, Republican Ron Johnson, has voiced support for counting ballots early, but state lawmakers have deadlocked on whether to permit it.

In the meantime, election officials say they feel well prepared to keep people safe as they show up to vote. The state held primaries in April and August, giving officials two opportunities to get a handle on the complexities of holding elections during a global disease outbreak in which unprecedented numbers of people are voting early.

Wisconsin also has a more decentralized approach to administering elections than most states, with municipalities taking the lead rather than counties. That makes it easier to recruit poll workers at the local level, which has been key as the state grapples with both the pandemic and the crush of mail-in ballots and early voting, McDonell said.

“We’ve been able to add a lot of younger poll workers and allow at-risk poll workers to stay home,” he told The Post. “And that’s good for us in the long term. We did lose a lot of experience, but we’ve had April and August to help with the hands-on learning.”

In Winnebago County, where Oshkosh is the county seat, County Clerk Sue Ertmer said local officials have been given hand sanitizer, spray sanitizer for surfaces, face masks, gloves and other protective equipment that the state started procuring during the April primary. They come to the county office in Oshkosh to pick up the materials along with election supplies such as ballot bags — and in some cases, Ertmer said, she has loaded equipment into her SUV and delivered it herself.

“We’re feeling good,” Ertmer said. “We’re just trying to properly space out and wear face masks and do what we need to stay healthy and keep working.”

In April’s primary, a shortage of poll workers contributed to long lines, lost ballots and general confusion as the first wave of coronavirus infections was taking hold in the United States. The situation has reversed in the six months since, with some polling places now overwhelmed with volunteers.

Gina Kozlik, the clerk for the city of Waukesha, said the recent increase in cases hasn’t dented poll worker recruitment or retention so far. Multiple poll workers withdrew during the April primary as the pandemic spiraled out of control. This time, she said, more than 300 are signed up for Election Day.

“Right now I’m fully staffed,” she said.

Even with the extra hands on deck, however, officials say they worry about people falling ill and calling out. To protect against that, Milwaukee has built a 20 percent no-show rate into its Nov. 3 plans. But smaller municipalities, where some clerks work only a few days a week, may not have the same safeguards.

“Their biggest concern is that they’ll have enough poll workers and that people won’t get sick or be afraid to work,” said Ertmer, of Winnebago County.

Wisconsin officials aren’t alone in preparing for the general election amid a steep increase in coronavirus cases. Infections have risen in nearly every U.S. state since September, with many Midwestern states registering their biggest surges to date.

Just before cases began to spike in Nebraska, election officials in Lancaster County, which includes the state capital of Lincoln, sent early vote applications to every registered voter on their rolls. Now, with statewide cases reaching record highs, they’re hoping the early action pays off.

“We hope that our efforts to get people to vote early will lessen the number of people on Election Day,” said county election commissioner David J. Shively. “We just don’t know what turnout is going to be like in what part of town."

Even in places where infections are relatively stable, the coronavirus has caused disruptions. In Okaloosa County, Fla., a branch of the Supervisor of Elections Office was closed just as early voting began this week after Supervisor Paul Lux and a colleague tested positive. Lux said in a statement he would follow recommendations for self-isolation and hoped to be back to work before Nov. 3.

Pandemic preparations were top-of-mind for some voters as well. Debra Mason, 66, was one of two dozen people waiting outside a senior center in Milwaukee before voting opened at 7 a.m. The administration’s coronavirus response made her more fired up to vote in person, she said.

“I haven’t voted in a long time but Trump brought me out,” Mason said. “He’s been ridiculous. … You’ve got people dying, and he treats it like a joke.”

Simmons reported from Milwaukee. Emily Guskin in Washington contributed to this report.