A president who once claimed that “the worst days of the pandemic are behind us” now acknowledges that it has surged through much of the country and will “get worse before it gets better.”

Credit…Doug Mills/The New York Times
WASHINGTON — He insisted that it was safe, that people could go back to work, that schools could reopen, that he could hold packed indoor campaign rallies, that he could even hold a full-fledged, boisterous, bunting-filled nominating convention as if all were well.

Only now, it is all crashing down around President Trump. The president who shunned masks and pressured states to reopen and promised a return to the campaign trail finds himself canceling rallies, scrapping his grand convention, urging Americans to stay away from crowded bars and at long last embracing, if only halfheartedly, wearing masks.

It may not be the death of denial, but it is a moment when denial no longer appears to be a viable strategy for Mr. Trump. For more than three years in office, he proved strikingly successful at bending much of the political world to his own vision of reality, but after six months the coronavirus pandemic is turning out to be the one stubborn, inalterable fact of life that he cannot simply force into submission through sheer will.

The president’s springtime confidence that he could cheerlead the country back to a semblance of normalcy in time to kick-start the moribund economy and power himself to a second term in November’s election has proved unequal to the grim summertime medical and autopsy reports emerging from the South and West. With 60,000 new cases and 1,000 more deaths being registered each day, Mr. Trump has been forced this week to retreat from the rose-colored assessment of the health of the nation — and his presidency.

Not that he has admitted a change. As he revived his coronavirus briefings this week, he still insisted that most of the country was doing well and offered upbeat predictions about conquering the virus. But his actions belied that view as he canceled the convention in Jacksonville, Fla., citing the same health care concerns that he had disparaged in shifting it abruptly from Charlotte, N.C., in the first place.

Even the decision to begin holding the briefings again was itself an admission that the crisis he wanted so desperately to be over in fact is accelerating even as he falls behind former Vice President Joseph R. Biden Jr. by double digits in the polls. Mr. Trump would have rather been talking about almost any subject other than the virus, but there he was again at the lectern three days in a row dutifully reading the warnings that his advisers had given him to read.

“This is a case when you line it all up, it’s the last season of ‘The Apprentice,’ we’ve got 100 days left and the reality TV star just got mugged by reality,” said Rahm Emanuel, who served in Congress and as White House chief of staff to President Barack Obama before becoming mayor of Chicago.

His defenders said Mr. Trump has responded to the situation as it has changed. “With this virus we entered a realm of unknown unknowns, making decision-making tough for anyone, including this president,” said Christopher Ruddy, the chief executive of Newsmax and a friend of Mr. Trump’s. “Considering the conflicting advice he’s gotten from medical experts, I think he’s done a great job on the economic response and a good job in lowering the daily death count. The public will eventually see that.”

In speaking before the cameras this week, White House officials insisted that Mr. Trump had not changed his view of the virus at all and that he always took it seriously. Speaking on the condition of anonymity, however, senior Republican officials express exasperation that the president in their view mishandled the virus, leaving the party vulnerable to not only losing the White House but the Senate as well.

The public has grown increasingly worried as caseloads soar to twice as high as they were during the earlier peak of the pandemic in March and April. Where just 30 percent of Americans believed the crisis was getting worse in early June, 66 percent now believe it is, according to Gallup. Three-quarters of those surveyed said they expected the disruption to travel, school, work and public events to continue until the end of the year or even into next year before the situation begins to improve.

A coronavirus testing site on Friday at Mountain View College in Dallas.Credit…Nitashia Johnson for The New York Times
He needed to be the pandemic president. Instead he became a pandemic denier,” said Dr. Jonathan S. Reiner, a prominent cardiologist who treated former Vice President Dick Cheney. “Unfortunately, when a president refuses to accept scientific reality,” Dr. Reiner added, “his words and actions are emulated by large numbers of Americans who then dismiss the seriousness of the pandemic with predictable disastrous consequences.”

From the start, Mr. Trump has repeatedly underestimated the virus, likening it to the flu, frequently predicting that it will simply “disappear” on its own, denouncing media “hysteria” over the disease, insisting that cases will go down to almost zero and then prematurely declaring victory in the war against it.

He said in March that “no way am I going to cancel the convention”and contended that “we’re going to be in great shape long before then.” A month later, citing health experts, he declared that “the worst days of the pandemic are behind us.” When North Carolina’s governor insisted that the convention in Charlotte would have to be limited by public health measures, Mr. Trump angrily moved most of it to Jacksonville, where he promised a full event.

By this week, he was grudgingly bowing to the reality that the virus has spread, not ebbed, admitting that it would “get worse before it gets better” and canceling Jacksonville, saying “it’s not the right time for that.” After his initial effort to resume arena rallies was a bust in Tulsa, Okla., and the second one scheduled for Portsmouth, N.H., was canceled, Mr. Trump now says he will conduct “telerallies.”

The rising infections have also forced Mr. Trump to be more supportive of masks after months of scorning them. When he first announced that public health experts wanted the public to wear masks, he immediately undercut the message by declaring that “I don’t think I’m going to be doing it,” complaining that it would not look good in the Oval Office as he greeted foreign visitors.

In the months since, he reposted a Twitter message that mocked Mr. Biden for wearing a mask, disparaged a reporter who insisted on wearing a mask to a news conference “because you want to be politically correct,” insisted that masks were a “double-edged sword” and agreed that some people might only be wearing masks to make a political statement against him.

Over the past two weeks, he wore one in public where he would be photographed for the first time and told Americans that it was an act of patriotism to wear one. “If you can, use the mask,” he said in a televised briefing. “When you can, use the mask.”

Even so, he has not worn one himself in public again, not even when visiting his Washington hotel for a political event or hosting Little League players on the South Lawn to mark the reopening of Major League Baseball.

Kayleigh McEnany, the White House press secretary, insisted on Friday that Mr. Trump had not adjusted his approach to the virus, saying he “has been consistent” on masks and always supported them. “He hasn’t changed,” she said. “The reason he wants to bring back these briefings is to get information out there.”

Kellyanne Conway, the president’s counselor, acknowledged that the spikes in infections followed states’ reopening, but blamed the governors. “Some of these states blew through our gated criteria, blew through our phases and they opened up some of the industries a little too quickly like bars,” she told reporters this week. Reminded that it was the president who had encouraged them to reopen quickly, she pointed to the one time he chided one state, Georgia, for going too far.

Mr. Trump and his team continued to insist that he had handled the virus decisively, always citing his decision early on to limit travel from China and the increases in the supply of ventilators and testing capacity. The president likewise continued to press schools to reopen fully and in person in the fall, even though his own son’s private school will not, but even there he gave some ground this week by acknowledging that some schools in areas hard hit by the virus might need to delay doing so.

But in much of the country, school leaders, like many governors and mayors, are paying less attention now to a president whose predictions have fallen flat and are paying more attention to the numbers on the charts. If a political convention in Jacksonville is not safe in the coronavirus age, many schools are coming to the conclusion that it may not be safe for them either, at least not on a full-scale basis.

“The virus and science, not politics, will determine spread of the virus and whether and when schools and our economy can reopen without having to slam shut again,” Thomas R. Frieden, a former director of the Centers for Disease Control and Prevention, said on Friday. “Facts matter. Science matters. Supporting and being guided by public health matters.”