Over the weekend, Rep. Devin Nunes (R-Calif.), a leading ally of President Trump, dismissed concerns about the coronavirus pandemic and said on Fox News that “it’s a great time to just go out, go to a local restaurant.”

And former New York City police commissioner Bernard B. Kerik, a Trump supporter who was pardoned last month, tweeted that “this hysteria is being created to destabilize the country, and destroy” Trump.

But from Italy, where there is a national quarantine to try to slow the devastating effects of the coronavirus, Newt Gingrich offered a different perspective. The former House speaker wrote an opinion piece seeking to convince his fellow Republicans that not only was the pandemic very real, it required urgent action.

Inside the Republican Party and the conservative movement that Trump commands, there is now a deep divide as the nation confronts the coronavirus. For weeks, many on the right, including Trump, minimized the virus, if they considered it at all. Even in recent days, as much of the world shuts down to try to stop its spread, some Republicans mocked what they saw as a media-generated frenzy.

Their reaction reflected how the American right has evolved under Trump, moving from a bloc of small-government advocates to a grievance coalition highly skeptical of government, science, the news and federal warnings.

Their conspiratorial unrest is particularly acute within right-wing media, where Fox Business removed a prime-time anchor for casting the coronavirus as “another attempt to impeach the president.” Other right-wing personalities continue to call the coronavirus a “hoax” or falsely blame George Soros, the billionaire investor and liberal donor, for causing it.

But conservatives and Republicans now face an undeniable reality as the pandemic’s death count here and abroad climbs — and the worldwide reach of the coronavirus defies the bounds of political debate.

“It’s damn clear that this is no hoax and should be taken seriously,” said Jason Miller, a former Trump campaign adviser who co-hosts a podcast with former White House chief strategist Stephen K. Bannon called “War Room: Pandemic,” which has documented the economic and health fallout of the coronavirus for weeks.

“The right underestimated this and thought the media was beating up on Trump again,” added GOP strategist Ed Rollins, who chairs a pro-Trump super PAC. “That was yesterday. Today is, ‘Life in America is changing before our eyes.’ ”

Trump has suddenly and markedly recalibrated his own approach, after weeks of blasé comments about the virus that spurred some of his allies to dismiss the danger of the pandemic.

When asked Monday about Nunes’s comment to Fox News, Trump did not echo him. Instead, Trump said he had not heard about the remarks, but would “disagree” with anyone calling on Americans to gather at restaurants.

“I think it’s probably better that you don’t,” Trump told reporters.

Hours later, Sen. Mitt Romney (R-Utah) said, “I’m pleased that the president and the public health officials seem to now be on the same page. I think there was a gap in the early days.”

A turning point for Trump came last week when Fox News host Tucker Carlson, whom the president regularly calls, said in his opening monologue: “This is real.”

“People you trust — people you probably voted for — have spent weeks minimizing what is clearly a very serious problem,” Carlson said.

Carlson’s riff caught Trump’s attention and was one of the factors that led the president to start to reconsider his position, according to two White House officials who requested anonymity to speak frankly.

“The conservative media echo-sphere was playing to the president’s worst tendencies, but you can almost time his turnaround publicly to how Breitbart and Tucker Carlson have been covering coronavirus,” said Sam Nunberg, who advised Trump on media in the run-up to his 2016 campaign.

Several top Republicans, including Oklahoma Gov. Kevin Stitt, have faced backlash for breaking with public health experts and shrugging off the call for social distancing, offering discordant messages to Americans who are looking to the government for clarity and guidance.

Dark conspiracy theories have also made their way into the forefront of conservative discussions about the pandemic.

David A. Clarke Jr., the former Milwaukee County sheriff and Trump booster, suggested on Sunday that the global panic about the coronavirus was being pushed by Soros — a common subject of anti-Semitic conspiracy theories — and urged people to take to the streets.

“Not ONE media outlet has asked about George Soros’s involvement in this FLU panic,” Clarke said. “He is SOMEWHERE involved in this.”

Twitter took down those tweets on Monday, citing its policy against “encouraging self-harm.”

Breitbart, a website once led by Bannon, has blanketed its pages in recent days with the coronavirus coverage. “War Room: Pandemic,” broadcasting out of Bannon’s home, has become another gathering place for conservatives who see the crisis as a defining test for the nation and for Trump.

Several Republican governors have contrasted with the politically charged response in Washington as they have dealt firsthand with the coronavirus and its impact. Ohio Gov. Mike DeWine has been a pacesetter, moving rapidly to close schools and some businesses, as has Maryland Gov. Larry Hogan, among others.

The virus has affected some of Trump’s biggest supporters. Days after Rep. Matt Gaetz (R-Fla.) wore an enormous gas mask during a House floor vote on an emergency funding package for the coronavirus response, the congressman announced that he would self-quarantine for 14 days after encountering someone at the Conservative Political Action Conference who tested positive.

Other Republican lawmakers who attended that conference, such as Rep. Paul A. Gosar (Ariz.), Sen. Ted Cruz (Tex.) and Rep. Douglas A. Collins (Ga.), announced they would self-quarantine even though they weren’t experiencing symptoms.

Sen. Tom Cotton (R-Ark.), meanwhile, has joined a right-wing clamor that has largely blamed China for unleashing “this plague on the entire world through their dishonesty and their lack of transparency and corruption.” His efforts come as other conservatives push to define the virus as “Chinese” rather than solely in medical terms, even as Americans with Chinese heritage face xenophobia and growing challenges.

“We’re shutting down our country because of the cold virus, which is what coronaviruses are,” Rush Limbaugh told his national radio audience last week. “You think the Chinese are not laughing themselves silly over how easy this has been?” He later added, “The Chi-Coms run this scam on some sort of virus, and the Americans do this?”

During this year’s State of the Union address, Trump awarded Limbaugh the Presidential Medal of Freedom “in recognition of all that you have done for our nation, the millions of people a day that you speak to and that you inspire.”

Historian Douglas Brinkley said Trump fueled Limbaugh and others with his early response to the coronavirus, which included sweeping travel restrictions on China as well as political shots at his critics.

“He lit up the conservative movement, which followed his lead,” Brinkley said. “They knew what to do when he intimated it might be a hoax — and they have seen him belittle institutions of government for years, from the CIA to the State Department to the FBI. That has had a corrosive effect on the country.”

Brinkley added that fierce partisanship, loyalty to Trump and a conservative media complex that is inclined to play up turbulence around Trump as unfair or “fake” has left the nation divided and on edge.

An NBC News-Wall Street Journal poll released on Sunday showed Republicans far less likely to be worried about the coronavirus, with 40 percent of Republicans sensing “the worst is yet to come” compared to 79 percent of Democrats. And 81 percent of Republicans approved of Trump’s efforts compared to 13 percent of Democrats.

Gingrich said in a phone interview from Rome — where his wife, Callista, is the U.S. ambassador to the Holy See — that many conservatives initially were prone to be dubious about the threat of the coronavirus because of “classic conservative distrust of big government” and “the bias and hostility they see in news coverage about the president that makes them assume that it’s one more lie.”

But, Gingrich said, those assumptions have started to fall away as headlines about the pandemic grip the nation.

“Facts matter,” Gingrich said. “It took a little longer for people to believe it, but they watched what happened in Italy and saw that it was not unique to China. That cut through and became real.”

Kim Bellware and Philip Bump contributed to this report.