When President Trump sought to reassure a nation on edge over the coronavirus, he was flanked Wednesday evening at the White House by more than a half-dozen public health experts.

But the very officials whose expertise the president is now counting on are part of the vast bureaucracy of scientists and other public servants that Trump has repeatedly maligned, ignored and jettisoned.

Throughout his more than three years as president, Trump has obsessed, at times conspiratorially, over what he calls the “deep state” — the thousands of career government specialists in national security, intelligence, science and other areas whose expertise he shuns in part because he suspects they are disloyal saboteurs.

And so, with the first case of coronavirus not tied to foreign travel being announced in California on Wednesday, Trump finds himself grappling with a crisis for which his record suggests he is particularly ­ill-suited to respond.

At a moment that demands sobriety and honesty, Trump is a leader prone to hyperbole and falsehoods. As the financial markets and the public crave order and clarity, Trump has a penchant for creating chaos and confusion. And at a time when expertise is paramount, Trump has hollowed out the government agencies responsible for the tasks at hand.

“People should speak without hyperbole and try to be cool, calm and collected and pay attention to the experts,” said Andrew Card, a White House chief of staff in the George W. Bush administration who helped manage the response to the 9/11 terrorist attacks and the SARS outbreak in the early 2000s. “Try not to be driven by emotion, and don’t say things that are not true. This is when you stick to the facts and don’t invite fear or impulsive behavior.”

Trump’s charge is to calm, rather than con, a frightened nation. But now in his fourth year in office, he lacks credibility with broad swaths of the country — the sort of safety net that many of his predecessors could fall back on in moments of crisis.

Stephen Morrison, a senior vice president at the Center for Strategic and International Studies, where he directs the center’s global health work, said that while the Centers for Disease Control and Prevention has done “a fine job” in regularly updating the public with guidance, “the trick and the missing part is the communications at a higher level to the American public, and that’s from the president and the president’s designated surrogates.”

Trump has already contradicted his top health officials. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, said Tuesday that it was not a question of “if” coronavirus spreads in the United States but “when.”

A day later, Trump offered a different assessment: “I don’t think it’s inevitable,” the president said at his news conference. “I think that there’s a chance that it could get worse. There’s a chance it could get fairly substantially worse. But nothing’s inevitable.”

He also claimed that the virus might dissipate by April, when the weather warms — but while some viruses do falter in warmer temperatures, there is no clear evidence that this coronavirus will behave similarly.

Ron Klain, who led the Obama administration’s response to the Ebola outbreak in 2014 and is now an adviser to former vice president Joe Biden’s presidential campaign, said a challenge for Trump in managing this crisis is his “desire to happy-talk away every problem.”

By downplaying coronavirus concerns, Klain argued, Trump may be “trying to pump the stock market, but the virus is not going to be persuaded by Trump’s tweets. He needs to communicate straightforwardly with the American people what’s happening.”

It is not the first time Trump has provided questionable information in the middle of a crisis. Last year, as Hurricane Dorian bore down on the Eastern Seaboard, Trump used a thick black Sharpie marker to doctor an official National Oceanic and Atmospheric Administration map to support his tendentious warning to the people of Alabama that the storm would probably hit their state.

Trump’s presidency has been guided by an ethos that then-candidate Trump articulated at the 2016 Republican National Convention in Cleveland: “I alone can fix it.”

Once in office, Trump shunned government experts. He shortened or tuned out some of his intelligence and national security briefings and rejected some of the conclusions of scientists. He relied on his instincts, rather than the expertise of those around him, to make decisions in virtually every realm.

“I have a gut, and my gut tells me more sometimes than anybody else’s brain can ever tell me,” Trump said in a 2018 interview with The Washington Post — a statement about his feud with Federal Reserve Chair Jerome H. Powell but one that also illustrates his overall governing philosophy.

In the scientific community, Trump has been similarly dismissive. By the spring of his first year in office, there were nearly 700 vacant positions at the CDC because of a hiring freeze that officials said would affect programs supporting infectious-disease control and health-emergency readiness.

Trump’s 2021 budget, submitted to Congress this month, proposes cuts to a broad array of health and scientific programs, including trimming the CDC’s funding by almost 16 percent and reducing overall funding for global health initiatives.

“You’re going to have to beat this with the ‘deep state’ — that is, the experts inside [the National Institutes of Health] and CDC and Homeland Security,” Klain said. “But there’s a general view in this administration that they don’t trust these permanent experts who’ve served Democratic and Republican administrations both.”

For Trump, the political stakes of bungling the coronavirus response could be devastating. The president and his advisers have long relied on robust financial markets, low unemployment and high consumer confidence to smooth his path to reelection. “I’ll be running on the economy,” Trump said in 2019.

But faced with fears of a global pandemic, U.S. markets fell sharply throughout the week — making it one of the worst weeks since the financial crisis of 2008.

Past presidents who have failed to manage crises have often faced swift political backlash. Bush struggled to recover from his handling of Hurricane Katrina in 2005, which left over 1,200 dead and displaced thousands more across the Gulf Coast. In the next year’s midterm elections, Bush’s Republican Party lost control of both houses of Congress.

“The Katrina comparison is very apt,” Morrison said. “This has potentially enormous consequences for the United States. It has enormous consequences that will touch many more citizens than Katrina touched, potentially.”

It remains unclear just how the coronavirus will play out — whether it will become Trump’s Katrina or, defying alarmist assumptions, prove a testament to Trump’s managerial prowess.

But already there are signs that the administration’s handling of the current crisis has assumed a distinctly Trumpian sheen. The president initially weighed in on Twitter while traveling abroad in India, offering an uncomfortable dissonance from the facts playing out on the ground in the United States and around the globe.

“Stock Market starting to look very good to me!” he wrote on the day the Dow Jones industrial average plunged more than 1,000 points. In another, later tweet, he misspelled the name of the virus as “caronavirus.”

Meanwhile, the president was fuming, in public and in private, over news coverage of the virus and the market collapse and quickly personalized the crisis. Trump accused news organizations and Democratic congressional leaders of intentionally trying to scare people to make him look bad.

Only upon his return to Washington, as he realized that the coronavirus was dominating all news cycles, did Trump decide to try to assume more of a leadership role, scheduling a news conference that he would lead Wednesday evening.

But even that had a slapdash quality. All day, reports of infighting among Trump’s top staffers, including Health and Human Services Secretary Alex Azar, leaked to the news media. And the president’s announcement that he was deputizing Vice President Pence to oversee all handling of the outbreak blindsided administration officials, including those deeply involved in the response.

The president — an avowed germophobe — also couldn’t help but insert himself squarely into the discussion. As he talked about preventive measures, he offered his own personal-hygiene perspective, suggesting people treat the coronavirus like the common flu.

“When somebody sneezes,” Trump began, “I mean, I try and bail out as much as possible when there’s sneezing.”