The death of Herman Cain, attributed to the coronavirus, has made Republicans and President Trump face the reality of the pandemic as it hit closer to home than ever before, claiming a prominent conservative ally whose frequently dismissive attitude about taking the threat seriously reflected the hands-off inconsistency of party leaders.

Mr. Cain, a former business executive and candidate for the Republican presidential nomination in 2012, had an irreverent, confrontational style that mirrored the president’s own brand of contrarian politics. In his more recent role as a public face for the president’s re-election campaign, he became an emblem of Trump-supporting, mask-defiant science skeptics, openly if not aggressively disdainful of public health officials who warned Americans to avoid large crowds, cover their faces and do as much as possible to limit contact with others.

His view was shared by many conservatives, who have applied a hard-nosed, culture war mentality to the virus, the most serious public health crisis in a century.

Mr. Trump wrote in praise of Mr. Cain on Twitter on Thursday, calling him “a Powerful Voice of Freedom and all that is good.”

But Mr. Cain’s death showed how ill-suited that mind-set is to the country’s current predicament. More than 150,000 Americans have died in a pandemic that is ravaging parts of the country where conservative leaders long resisted taking steps that have slowed the virus elsewhere, such as mask mandates and stay-at-home orders.

Those include places like Tulsa, Okla., where Mr. Cain attended a Trump campaign rally in June and showed his disregard for safety precautions on social media shortly before receiving a diagnosis for the virus.

With a uniformity that has defied rising death tolls in their own backyards, Republicans at the federal, state and local levels have adopted a similar tone of skepticism and defiance, rejecting the advice of public health officials and deferring instead to principles they said were equally important: conservative values of economic freedom and personal liberty.

From Arizona to Texas, as infection rates soared and hospital beds filled up, Republican governors stood in the way of local governments that wanted to do more. They overruled city mask mandates, arguing that it amounted to a form of government overreach. They said that requiring businesses to close or limit their capacity would strangle the economy and save few lives. They accused the news media and political opponents of exaggerating the risks to hurt the president’s chances for re-election.

They scorned the experts and mocked those who heeded the government’s warnings. Representative Matt Gaetz of Florida, a close ally and vigorous defender of the president, walked around the Capitol in March wearing a Hazmat-style gas mask as he prepared to vote on coronavirus relief legislation.

The governor of Oklahoma, Kevin Stitt, posted a picture of himself eating dinner with his family at a crowded restaurant a few days after the World Health Organization formally declared a pandemic. “It’s packed tonight!” his caption read.

And this month in Missouri, Gov. Mike Parson scoffed at the idea of a mask mandate, telling a cheering crowd of supporters, “You don’t need government to tell you to wear a dang mask.”

Yet the virus more than occasionally reminded them that it strikes people of all political stripes indiscriminately.

After his mask stunt, Mr. Gaetz learned that he might have been exposed to someone who was infected and attended the Conservative Political Action Conference. He said he would enter quarantine, and he did not end up having the virus. Mr. Stitt tested positive for the virus this month, the first governor in the country to do so. He continues to resist pressure to issue a mask order, calling it “a personal preference.”

And this week, adding to the list of people with direct access to the president who have tested positive was Robert C. O’Brien, the national security adviser. Others include Kimberly Guilfoyle, a former Fox News commentator who is dating Donald Trump Jr. and is helping lead the Trump campaign’s fund-raising efforts.

Among some conservative defenders of the president, there is a sense that complaints about masks and other mandates as a threat to personal freedom are overblown.

Grover Norquist, a conservative activist who lobbies for lower taxes and regulations and has served on the board of the National Rifle Association, said that using Mr. Cain’s death to attack Republicans “is going two steps too far.” But he added, “There’s a difference between not being excited about being told what to do” and refusing to do it altogether. “But on something like this, when you’re out in public, you should wear a mask because it’s not about you.”

Yet there have been few indications that the spate of coronavirus cases among Republicans is leading to any kind of major reckoning in the party. After Representative Louie Gohmert of Texas tested positive this week, he blamed his diagnosis on wearing a mask.

Mr. Trump, who has spoken of being rattled by the death of an old friend who contracted the virus, has been photographed only rarely with a mask on and has repeatedly said he does not consider wearing one the appropriate step for him. He has allowed, however, that he is supportive of mask-wearing by others.

The visuals that emerged from the White House from the beginning of the pandemic suggested an attitude that was, at best, not overly cautious. At an event at the White House in March with executives from Walmart and Walgreens in which Mr. Trump praised his administration’s preparedness, he shook hands and patted the backs of multiple people, prompting critics to complain that the president was sending mixed signals to the public.

When the virus re-emerged after it initially appeared to have been subdued, it took weeks of public pressure and private lobbying by advisers and friends before Mr. Trump more frankly acknowledged the toll the resurgent virus has taken across the American South and West.

Even some of the harshest critics of Republican leadership said they did not think that Mr. Cain’s death would cause much reflection inside the party.

Evan McMullin, who ran against Mr. Trump as a third-party candidate in 2016, wrote on Twitter that Mr. Cain was “the first senior casualty of the science denial Trump cult.”

In an interview, Mr. McMullin said he had little hope this was a wake-up call. “I wish that was the case,” he said. “Many voters who support the president live in a totally different, alternate information environment in which the news of Herman Cain’s death — his visit to the Trump rally, his decision to not wear a mask — won’t reach them.”

Mr. Cain was eager to display his disregard for the experts and their warnings. Before the Trump rally in Tulsa, which local public health officials had urged the campaign to postpone, Mr. Cain urged people to “Ignore the outrage” and to defy “the left-wing shaming!”

Mr. Trump did at one point reschedule the rally, but only after an outpouring of anger that it had been scheduled for the day of Juneteenth, the holiday commemorating the emancipation of slaves.

When the rally went forward on June 20, Mr. Cain, one of the most prominent African-American Trump supporters and a member of his Black Voices for Trump coalition, posed for a photo with other Black attendees. None, including him, wore masks.

A few hours before the event, the campaign had disclosed that six Trump campaign staff members who had been working on the rally had tested positive for the coronavirus during a routine screening.

Mr. Cain tested positive on June 29. On July 2, his staff announced that he had been hospitalized. Weighing in on the no-mask policy for a Trump rally planned at Mount Rushmore on July 3, Mr. Cain’s Twitter feed was approving: “PEOPLE ARE FED UP!”