The mixed-to-negative views of Trump’s handling of the coronavirus emergency also poses a significant threat to his reelection prospects, now that former Vice President Joe Biden has emerged as the presumptive Democratic nominee and the virus threatens to become the dominant issue of the 2020 campaign.

“There’s no ‘rally ‘round the flag’ because people see he hasn’t been handling it well,” said Margie Omero, a Democratic pollster who collaborates on a Navigator Research project that has been tracking public opinion of the outbreak and Trump’s response.

On Wednesday, six separate pollsters released new surveys. In all six, Trump’s approval rating was below 50 percent, ranging between 40 percent and 45 percent. And each suggested Americans had at best a mixed opinion of his response to the virus, and those with trendlines from weeks earlier in the crisis showed an uptick in the percentage of those critical of Trump’s response.

Trump’s low approval ratings early in a crisis defy historical precedent. Presidents, dating back to the start of the modern polling era after World War II, typically see their approval ratings rise significantly when the country faces emergencies, though they more typically occur around international conflicts, mostly involving the military.

According to Gallup’s archives, John F. Kennedy’s approval rating stood at 61 percent at the start of the Cuban Missile Crisis in the fall of 1962, but it had surged to 74 percent a month later.

In October 1979, Jimmy Carter had a 31 percent approval rating. But after the siege of the U.S. embassy in Iran, Carter’s approval topped 50 percent in early December and hit a high of 58 percent in January 1980. It didn’t begin sagging again until the spring of 1980, and Carter was defeated by Ronald Reagan in November.

More recently, George H.W. Bush’s approval rating shot up from 58 percent in early January 1991, to as high as 87 percent following the climax of Operation Desert Storm, the U.S.-led military action to drive Iraqi forces out of Kuwait.

Bush’s son, George W. Bush, had a 51 percent approval rating in the Gallup poll conducted in the four days leading up to the Sept. 11, 2001 terrorist attacks. By the end of the month, as Bush handled the immediate recovery and investigation, his approval rating hit 90 percent.

Trump, by contrast, saw only the slightest increases in his approval ratings. According to the RealClearPolitics average, his approval rating stood at 44.5 percent a month ago, on March 8. By last week, it had ticked up to 47.4 percent — but as of Wednesday afternoon, including the new polls, it was back down to 45.2 percent.

“We saw something,” said Patrick Murray, the director of the Monmouth University Polling Institute. “Whatever we saw was certainly not anywhere what the typical rally effect would look like, but there was a slight bump for him.”

Monmouth’s new poll, out Wednesday, showed Trump’s overall approval rating at 44 percent, down slightly from 46 percent last month, during the early days of the crisis.

In the new Monmouth poll, 46 percent of respondents said Trump was doing a good job dealing with the coronavirus outbreak, while 49 percent said he was doing a bad job. Last month, 50 percent said Trump was doing a good job, compared to 45 percent who said he was doing a bad job.

That slightly increasing dissatisfaction with the federal response to the crisis was echoed in other polls. A new CNN/SSRS poll out Wednesday showed 45 percent of Americans approve of the way Trump is handling the outbreak, while 52 percent disapprove. The previous poll was conducted in early March — days before any significant restrictions or physical and social distancing measures were recommended — and it showed a similar, 7-point spread between the percentages of Americans who disapproved and approved of Trump’s performance on the issue.