WASHINGTON — For the first time Monday, President Donald Trump laid out a truly bleak picture of America in the time of coronavirus — pointing to an "invisible enemy" he said could plunge the nation's economy into recession and possibly even require quarantines of geographic "hot spots," if not the whole country.

The abrupt shift in tone matched a more gradual acceptance by the president that his response to the pandemic so far has failed to inspire confidence in the public, investors and lawmakers. Last week, he delivered an Oval Office address and a Rose Garden press conference that sent the mixed signal he was taking the threat of the disease more seriously, yet still didn't fully grasp the risk at hand.

His salesman's tendency to minimize the downside and play up the bright side left him looking like he couldn't judge the gravity or complexity of a situation that his own aides described in catastrophic terms.

By Monday, with more experienced federal and state officials proposing new restrictions on public interactions and economic relief packages in the hundreds of billions of dollars, Trump had largely dispensed with the happy talk. But given his own dire forecast, the time it took for him to understand the problem may have been costly in terms of the health and economic standing of the nation.

"We'd much rather be ahead of the curve than behind it," he said at a briefing for White House reporters.

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He was talking about the administration's response to the spread of the virus itself, but he might as well have been speaking to the various consequences of failing to adequately prepare the public for the toll that could be taken in terms of lives and economic destruction. The less ready, the more damage — in terms of health, the economy and, as a result of the first two, Trump's political fortunes.

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That is, all the facets are inter-related. Trump's trouble communicating the seriousness of the pandemic to the public — for weeks, he assured Americans it wasn't a big threat — may have been costly in terms of raising awareness about the best protocols to contain the spread.

"When you’re dealing with an emerging infectious diseases outbreak, you are always behind where you think you are if you think that today reflects where you really are," Anthony Fauci, the head of the National Institute on Allergy and Infectious Diseases, said while standing near Trump.

As they spoke, the Dow Jones Industrial Average finished the sharpest single-day point drop in its history, falling nearly 3,000 points, or almost 13 percent, to close at 20,188.52.

It shouldn't have been a surprise to the president that casting the crisis in darker terms might rattle investors immediately. For three-plus years, he's spoken only in the most optimistic terms about the stock market and the economy. That changed Monday.

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"Well, it may be," he said when he was asked if the economy was headed for a recession. Later, he added that "the best thing I can do for the stock market is we can get through this crisis."

Save for giving himself a perfect "10" on handling the response to coronavirus, the words coming out of Trump's mouth were hardly recognizable. He praised the media for being "fair" in its coverage and clarified that when he said that things were "under control" Sunday he only meant the government's efforts were coordinated.

The other major shift was Trump's emphasis on stopping the virus to the exclusion of concerns about the health of the economy. He announced a new set of guidelines for the public to combat the spread of the pandemic, including educating kids from home, limiting social gatherings to 10 or fewer people, avoiding bars and restaurants, and ending discretionary travel.

"We have an invisible enemy," he said. "My focus is really on getting rid of this problem, this virus problem. Once we do that, everything else is going to fall into place."

From what administration officials and outside experts have said, there was no time to waste in grasping the severity of the crisis and concentrating on fighting it. Trump seemed to get that Monday. The question, given the damage already done, was how easy it would really be to get "everything else" to "fall into place" later.