Former Vice President Joseph R. Biden Jr., the Democratic nominee, has said repeatedly that if he were to win the presidency, he is hopeful Dr. Fauci would remain in his role and serve in his administration.

Mr. Trump has adopted Florida as his home turf, and it is a swing state that he desperately needs to win to open paths to another four-year term. Although he narrowly prevailed there in 2016, polls, including one released Sunday by The New York Times and Siena College, have shown him trailing Mr. Biden in a tight race.

Roughly 8.7 million Floridians had already voted as of Sunday, according to the U.S. Elections Project, almost two-thirds of all registered voters in the state. But at least as of Sunday night, turnout among Black and Hispanic voters, both key groups for Democrats, has been lagging in Miami-Dade County, the most populous county in the state.

“We win Florida,” Mr. Trump said at the rally, “we win the whole thing.”

“Always look where I am,” a man coached a young girl in coveralls, telling her to stay close as they held hands and wove through the Omaha crowd waiting for Mr. Trump. “But these are Trump supporters. You don’t have to worry.”

It’s what made the phone call Mr. Rempel received about two weeks ago from fire officials as he and his wife were readying their children for school all the more shocking. His farm equipment was in flames. The combine, a tractor and two semitrailer trucks parked in a corn field south of town apparently had been set on fire

“I said, ‘No, that’s not possible,’” Mr. Rempel, a fourth-generation farmer, recalled, describing his disbelief that his equipment had been destroyed and his corn harvest put in jeopardy.

Nearly four years ago, in his election night victory speech, Mr. Trump pledged to fight for the “hard-working men and women who love their country and want a better, brighter future for themselves and for their family.”“The forgotten men and women of our country,” he promised back then, “will be forgotten no longer.”

For his part, Mr. Rempel refuses to speculate about a motive, but here in Henderson, a certain fear is being whispered: The fire-starters are aligned with antifa, coming from the cities to attack their way of life.

Like most other states, Nebraska is cleaved by an urban-rural divide. Mr. Trump won overwhelming support from the state as a whole. But people in Nebraska’s two major cities tend to vote more liberally than those in rural areas. Mr. Trump won in Omaha’s Second Congressional District in 2016, but Barack Obama won in 2008. The district’s winner picks up a single electoral vote in a state that, unlike most others, splits its votes, which could play a pivotal role in a close election.

Ms. Goossen and other supporters of Mr. Trump speak with reverence about the president’s plain talk, how he isn’t a typical pontificating politician, how he, a real estate mogul from New York City, can relate to all strata of society.

The president has been on job sites and spoken to workers “hauling drywall and raising steel,” said Blake Collingsworth, who runs a home-building business in Lincoln.

“I love being in flyover country. I love it. I embrace it,” Mr. Rempel said, walking through his rows of corn and fretting over every bent stalk. “I lived in Omaha. Nobody knew who you were. You could do whatever you wanted. You could go steal a car and run into a post and run away and nobody cares.”

On the one extreme is President Trump, who leaves little subtlety in his approach: Bragging about his sexual prowess, along with the size of his nuclear button, proclaiming “domination” over coronavirus and mocking his opponent for the size of his mask (“the biggest mask I’ve ever seen”), as if mask-wearing is somehow weak.

He has said he believes men who change diapers are “acting like the wife.” “Macho Man” is the song that plays at his rallies, even after the Village People objected. “He seeks to distinguish himself as the manliest — and thus, in his mind, the most-qualified — person to be president,” said Kelly Dittmar, a scholar at the Center for American Women and Politics at Rutgers University.

On the other end of the spectrum, or perhaps somewhere in the middle, is Mr. Biden, a “Dad-like” figure, as the philosopher Kate Manne put it, who has vowed to be America’s protector through a dark period, with some combination of strength, empathy and compassion.

“He’s offering a more paternalistic type of masculinity, in that you can be a strong leader, but still be compassionate and empathetic,” said Marianne Cooper, a sociologist at Stanford University who studies gender and work.

“Ultimately, masculinity still matters, we’ve learned. It’s how candidates still try to prove they are the best candidate,” said Ms. Cooper. “And so, even in 2020, Democrats decided the safest bet to beat a white man in his 70s is another white man in his 70s.”

From Richard Nixon to Ronald Reagan and right on through Mr. Trump, largely white, Christian, heterosexual presidential candidates have “performed” manhood in all sorts of ways: Donning hard hats and posing inside military tanks; battling over who would be the better guy to have a beer with; and implying their opponents were soft, weak, or “sleepy.”

“Michael Dukakis had a 17-point lead over Bush in the summer of 1988,” said Mr. Katz, whose book on presidential masculinity has been adapted into a documentary called “The Man Card.” “So what did they do? They relentlessly attacked his manhood. They suggested he was a failed protector, that he was ‘soft,’ that he wasn’t a ‘real man.’”

“I think the performance of masculinity means a lot,” he noted, “because it has the potential to eclipse all else.”

Girls receive a message that they “become” women — typically through a biological event like menstruation — while men are told throughout their lives to “be” men or to “man up,” as if masculinity is something that can be easily lost.“You don’t really say ‘be a woman’ the way you say ‘be a man’ or ‘man up,’” she said.Image

“Trump is the personification of this masculinity contest culture,” Ms. Cooper said. “It’s bad for organizations, it’s terrible for a country.”

Maybe women were always the intended audience for the contests. Whether that’s true, they seem to be ready to render a clear judgment. Mr. Biden is leading among women by as much as 20 points.

Mr. Trump was holding rallies in five states on Sunday after spending a full day in Pennsylvania on Saturday.

Mr. Biden has also faulted Mr. Trump for endangering his own supporters.“I’m being responsible and I’m not becoming a great spreader of Covid,” Mr. Biden said last week, making explicit the distinction that he has been trying to draw for months. Mr. Trump, he said, is “putting thousands of people at risk.”

Mr. Trump bragged about attracting bigger crowds than Mr. Biden and former President Barack Obama, who campaigned together on Saturday. “I hate to say it, Obama doesn’t draw any better,” he said. “They went as a twosome and they had less people.”

But Mr. Trump is less enthusiastic when the input comes from smaller crowds. On Saturday morning, as he spoke to only about 300 people at his first Pennsylvania rally of the day, Mr. Trump was lethargic and subdued, as if he were privately thinking to himself: Yawn.

“A great red wave is forming,” Mr. Trump said on Saturday in Newtown, Pa. “As sure as we’re here together, that wave is forming. And they see it, they see it on all sides, and there’s not a thing they can do about it.”

“It’s a great way to show the enthusiasm and get the feeling of a campaign while being Covid safe,” said Jenn Ridder, the national states director for the Biden campaign. “People love them. They love the honking and the noise. I think people want to feel part of something, and especially in Covid.”

“The horns can be really cool as far as call and response,” said Lt. Gov. Garlin Gilchrist II of Michigan, who spoke at the rallies in Flint and Detroit. “You have people kind of sitting on top of their cars, or hanging out the window.”

“It kind of personifies this campaign,” Mr. Gilchrist added. “Joe Biden is a person who values human connection.”

But the format allows for something that has been missing when Mr. Biden gives speeches during the pandemic in front of small groups of reporters: audible feedback from the crowd, even if it is different from the applause at Mr. Trump’s rallies.

Despite his campaign spending $10 million over the past two years on some of the most sophisticated data available, the president prefers to use what he sees on the news.

This week, Mr. Trump’s son-in-law and senior adviser, Jared Kushner, gave his own view of how polling works to Fox News, trumpeting “big data modeling” over old-fashioned phone calling.

“I do believe that polling with phones to people is an obsolete method, especially in the era of cancel culture. You’ve got a lot of snake oil salesmen who have kind of been in the business for a long time and they do this.”

Complaining that polls are “skewed” against Republicans has been a vocal pastime of Republican candidates for several election cycles, reaching a high pitch in 2012, when Mitt Romney was the party’s presidential nominee.

The Trump campaign has spent years and presumably millions of dollars engaging white voters without college educations who are eligible to vote but did not vote in 2016. There are almost 1.5 million such potential voters in Michigan and more than two million in Pennsylvania.

Beyond the polling, the fundamentals shaping the electorate, like the economy and the record-breaking coronavirus surge, are “increasingly ominous” for Mr. Trump, said Liam Donovan, a veteran Republican strategist.“Ironically, the polls may be the best thing the Trump campaign has going for it at this point,” he said.

Mr. McCleary’s estimates of Mr. Trump’s poll standing are less “negative” than some other Trump pollsters, according to people close to the campaign.

Mr. Trump devoted Saturday to four rallies across the state, and he and Mr. Biden planned campaign events for the final 48 hours of the race as well, with a wave of prominent Democrats and celebrities slated to arrive

In Pennsylvania in particular, the possibility of extended court battles and confusion hangs over the race, with the state Republican Party hoping the Supreme Court will reconsider its decision last week to allow the state to continue receiving absentee ballots for three days after Election Day.

The Texas Supreme Court denied an effort by Republicans to throw out more than 120,000 votes that had been cast at drive-through locations in Harris County, an increasingly Democratic area anchored in Houston.

in Dubuque, Iowa, on Sunday, Mr. Trump claimed, inaccurately, that the result of the election was always determined on Election Day. “We should know the result of the election on Nov. 3,” he said. “The evening of Nov. 3. That’s the way it’s been and that’s the way it should be. What’s going on in this country?”

Mr. Trump entered the final hours of the race in a worse position here than he was four years ago, when Pennsylvania was seen as Hillary Clinton’s firewall. This time, Mr. Biden has a lead of six points, according to a new New York Times/Siena College poll released Sunday, and is working to create multiple pathways to 270 electoral votes.

Mr. Trump’s lagging position in the race was evident in his grueling travel schedule that had him shoring up votes in five states he won four years ago — Michigan, Iowa, North Carolina, Georgia and Florida.His final rally of the day was scheduled for 11 p.m., and risked violating a midnight curfew in Miami-Dade County.Mr. Biden, by contrast, set his sights squarely on Pennsylvania on Sunday, an approach he will repeat again Monday, along with a foray into Ohio, a state Mr. Trump won handily in 2016 but that polls show could be more competitive now.

Mr. Biden countered with his own warning later Sunday, saying, “The president is not going to steal this election.”

Mr. Biden’s Philadelphia events kicked off a last push through the state over the final two days. On Monday, Mr. Biden, Senator Kamala Harris and their spouses are expected to campaign in five media markets, hoping to cement support across a sprawling coalition and to keep Mr. Trump’s margins down in parts of western Pennsylvania that propelled him to victory in 2016.“My message is simple,” Mr. Biden said Sunday. “Pennsylvania is critical in this election.”

Democrats are well aware of how devoted Mr. Trump’s core base remains. In Macomb County in Michigan, where the president held his first rally Sunday, Irwin Patterson was selling Trump merchandise at a makeshift roadside store.

He also embraced the actions of some of his supporters in Texas who had surrounded a Biden campaign bus with their vehicles on Saturday, in an apparent attempt to slow it down and run it off the road. Mr. Trump claimed the vehicles were “protecting his bus, yesterday, because they are nice.”

Compared with other swing states, such as Florida, far fewer early ballots have already been cast in Pennsylvania and, according to the U.S. Elections Project, as of Sunday there were more than 350,000 absentee ballots that had been requested by Democratic voters that had yet to be returned.

That lead, however, isn’t enough to make Democrats and anti-Trump Republicans feel fully confident about the state of the race in Pennsylvania.

The Trump campaign ads running in Pennsylvania have been overwhelmingly centered on economic messages, mainly jobs and taxes.

Pennsylvania saw its unemployment rate fall to 8.1 percent in September, according to the Labor Department, nearly identical to the national rate of 7.9 percent.

“That blue wall has to be re-established,” Mr. Biden said in another recent Pennsylvania campaign appearance. He said that winning the state meant a “great deal to me, personally as well as politically.”

Pennsylvania has long loomed large in the psyche of the Biden campaign. Mr. Biden, a Scranton native, gave his first speech of his presidential campaign in Pittsburgh, and he chose Philadelphia for his campaign headquarters, before the pandemic hit.

Pennsylvania’s economy is emerging from the pandemic recession but still has a long road ahead to its pre-crisis state. Like the nation, it has seen a two-track recovery that has left small businesses and low-earning workers behind.

According to a national survey conducted by The Upshot and Siena College, they aren’t so much fretting about themselves as they are anxious about the country.

They fear the next generation in America will be worse off. Even some voters who say they are personally better off than four years ago say the country as a whole is worse off.

“I’ve never felt this way about our country,” said Jerry Thatcher, a 76-year-old Trump voter in Yamhill, Ore.

Diane Haller, a 50-year-old Biden supporter in Avon, Ohio, says President Trump has threatened the country’s foundations by bending the Department of Justice to his personal ends. “How is a democracy going to work if that’s allowed?” she said. “We’re just teetering, and it’s scary as all get-out.”

“I guess an email is notification of exposure,” said Erin Sanders, a nurse practitioner and certified contact tracer in Boston. “But that is not contact tracing,” she said, “and not how a responsible public health agency handles a super-spreading cluster of a deadly virus.”

an internal C.D.C. email on Friday asked the agency’s scientists to be ready to go to Washington for contact tracing, but a request from the White House for assistance never came, according to two senior C.D.C. scientists.

Experts at the C.D.C. could have immediately put in place contact tracing for President Trump and others who have been infected, working with health departments of the states to which Mr. Trump and others have traveled. But regulations require that the C.D.C. be asked to step in.

During the 48-hour window before Mr. Trump’s diagnosis that White House contact tracers are focusing on, the president debated former Vice President Joseph R. Biden Jr. in Cleveland; traveled to a rally of thousands in Minnesota; met with supporters and donors at his golf club in Bedminster, N.J.; and conferred with dozens of aides at the White House, all while not wearing a mask.

The timing of the diagnosis of Mr. Trump’s illness makes it highly likely that he and the others became infected on Saturday, medical experts said. Symptoms typically appear around five days after exposure to the virus; Mr. Trump began showing symptoms on Thursday, “right smack dab in the day” he would be expected to, Dr. Maldonado said.

“Staff should not go to the White House Medical Unit clinic for any Covid-19 testing inquiries,” the memo said. But some officials have continued to go to work.

An American official briefed on the intelligence said it was wrong to equate the two countries. Russia, the official said, is a tornado, capable of inflicting damage on American democracy now. China is more like climate change, the official said: The threat is real and grave, but more long term.

Iran was seeking “to undermine U.S. democratic institutions, President Trump, and to divide the country”

Mr. Trump said, “The last person Russia wants to see in office is Donald Trump because nobody’s been tougher on Russia than I have.” He said that if Mr. Biden won the presidency, “China would own our country.”

“Donald Trump has publicly and repeatedly invited, emboldened and even tried to coerce foreign interference in American elections,” said Tony Blinken, a senior adviser to the former vice president.

“The director has basically put the American people on notice that Russia in particular, also China and Iran, are going to be trying to meddle in this election and undermine our democratic system,” said Mr. King, a member of the Senate Intelligence Committee.

Russia, but not China, is trying to “actively influence” the outcome of the 2020 election, said the American official briefed on the underlying intelligence.

Intelligence and other officials in recent days have been stepping up their releases of information about foreign interference efforts, and the State Department has sent texts to cellphones around the world advertising a $10 million reward for information on would-be election hackers.

his plummeting blood oxygenation, high fever and treatment with medication reserved for patients with severe Covid-19. Yet Mr. Trump and his team have insisted on projecting a rosy image of a president nearly undisturbed by his illness.

Mr. Trump told his Twitter followers today not to fear Covid-19 and “don’t let it dominate your life,”

Often the deceptions and exaggerations spread by Mr. Trump and his allies have been about the president’s image and self-regard: the size of his rallies, for example, or his net worth or charitable foundation.

His health is a far more serious matter, one that puts national security at risk.

Mr. Biden, whose campaign said he had tested negative for the coronavirus on Sunday,

But on Monday, after the president unleashed a flurry of all-caps tweets urging his supporters to vote, Mr. Biden issued several sharp remarks about the administration’s approach to the virus, even as he expressed well wishes for the president’s health.

Mr. Biden said during an address that he delivered in the Little Havana neighborhood of Miami while wearing a mask. “Now that he’s busy tweeting campaign messages, I would ask him to do this: Listen to the scientists. Support masks. Support a — mask mandates nationwide.”

Mr. Trump left the hospital after tweeting in reference to a disease that has killed more than 209,000 people in the United States: “Don’t be afraid of Covid. Don’t let it dominate your life.” He emphasized that message in a video he posted on Twitter soon after arriving back at the White House.

“There’s a lot to be concerned about,” Mr. Biden responded on NBC, noting the death count. “I hope no one walks away with the message, thinking that it is not a problem. It’s a serious problem.”

“President Trump cannot advance democracy and human rights,” Mr. Biden said, “when he has embraced so many autocrats around the world, starting with Vladimir Putin.”

“I look like a socialist?” Mr. Biden said. “I’m the guy that ran against the socialist, remember? I got in trouble through the whole campaign, twenty-some candidates — ‘Joe Biden was too centrist, too moderate, too straightforward.’ That was Joe Biden.”

“Cuba is no closer to freedom and democracy than it was four years ago,” he said, arguing that the current “administration’s approach is not working.”

Does he realize that the reason his party has never offered an acceptable alternative to the A.C.A., in particular an alternative that would protect pre-existing conditions, is that no such alternative is possible? That’s less clear.

The second part of this statement may come as news to many readers, because Biden’s health proposals haven’t drawn much attention so far.Why not? One reason is that the election is — rightly — being seen mainly as a referendum on Trump rather than on likely Democratic policy.

Joe Biden, if he wins (and gets a Democratic Senate), will make a big difference in the other direction, substantially expanding coverage and reducing premiums for middle-class families.

To the extent that the Biden plan has received any attention at all, this attention has largely been focused on his proposed introduction of a “public option” — a Medicare-like plan that individuals could buy instead of purchasing private insurance.

First and foremost, the Biden plan — Bidencare? ObamaBidencare? — would substantially increase the subsidies that currently help many but not all Americans who don’t get insurance from their employers.

So the Biden plan would increase subsidies and also remove the upper-income limit that prevents many middle-class families from receiving aid.

The Committee for a Responsible Federal Budget puts the price tag at $850 billion over a decade. But it would cost far less than the 2017 tax cut, much of which went to corporations, which were supposed to respond by increasing investment, but didn’t.

The Biden plan would also automatically enroll low-income Americans in the public option, which is more important than it might sound.

“When a storm moves slower, it lingers longer over the same location,” said Kimberly Wood, a geoscientist at Mississippi State University. “A rain rate of, say, an inch an hour — that’s not so bad if the rain only lasts 30 minutes. But if it lasts for half a day, that adds up quickly.”

Climate change has also led to wetter storms, Dr. Wood said, because warmer air holds more moisture. Between the slowing speeds and increasing moisture, with storms like Sally “there’s a combination effect,” she said.

Researchers increasingly see a link between stalling of hurricanes and climate change.

by lingering for longer, the storm may also have boosted storm surge, the wind-driven buildup of water that can quickly flood coastal areas, often with devastating results.

Senator Patty Murray of Washington, the top Democrat on the Senate committee that oversees the Department of Health and Human Services, urged Mr. Azar to fire Mr. Caputo.

he was under stress because of questions about his physical health and threats to his safety and that of his family. He apologized for embarrassing Mr. Azar and the department.

A department spokeswoman called Mr. Schumer’s comments “uninformed” and misleading, and an effort to discredit “the historic work of the Trump administration” in battling the pandemic.

Mr. Caputo, a media-savvy former Trump campaign aide with no background in health, has worked aggressively to control the media strategy on pandemic issues.

The New York Times and other news outlets published accounts of how Mr. Caputo and a top aide, Dr. Paul Alexander, had routinely worked to revise, delay or even scuttle the core health bulletins of the Centers for Disease Control and Prevention in an effort to paint the administration’s pandemic response in a more positive light.

In Oregon, with a confirmed death toll of 10 along with 22 others missing

“Something’s happening to the plumbing of the world, and we come from a perspective, humbly, where we submit the science is in and observed evidence is self-evident that climate change is real, and that is exacerbating this.”

At his subsequent briefing, however, Gov. Gavin Newsom and his top environmental adviser pushed the president to acknowledge the role of climate change. Mr. Newsom, a Democrat, made a point of doing so exceedingly politely, reaffirming his working relationship with the president, thanking him for federal help and agreeing that forest management needed to be improved.

Mr. Biden, on the other hand, has proposed spending $2 trillion over four years to escalate the use of clean energy and ultimately phase out the burning of oil, gas and coal. He has pledged to build 500,000 electric vehicle charging stations, build 1.5 million new energy-efficient homes and eliminate carbon pollution from the power sector by 2035.

Mr. Trump rejected the premise. “It’ll start getting cooler,” he insisted. “You just watch.”

Not far away, one of the biggest fires, now largely contained, recently burned more than 363,000 acres.

Some environmental specialists said that Mr. Trump had a point about forest management but that it should not be an excuse to deny climate science and refuse to take action.

Experts say climate change, the management of public lands and decisions over where to site housing all contribute to wildfires. Mr. Trump has exclusively blamed poor forest management and last year issued an executive order directing agencies to cut down more trees, arguing that expanding timber harvesting would reduce forest fires.

“Well, I don’t think science knows, actually,” Mr. Trump retorted, maintaining a tense grin.