Trump’s positive test rippled across his political apparatus. With fears of infection rising, the reelection effort is preparing for a deep clean of its Arlington, Va., headquarters this weekend. Campaign manager Bill Stepien, meanwhile, sent a memo to staff saying that anyone “who has had exposure to someone testing positive should immediately begin self-quarantine.”

Perhaps most profoundly, the Trump team is being forced to reconsider its strategy for the final stretch of the campaign. After spending months trying to divert attention from the president’s management of the pandemic, the coronavirus is now certain to dominate the rest of the race.

“The debate over the last few weeks shifted to the [Supreme] Court and the economy, and that shift was helpful to Trump in drawing attention away from Covid. Coronavirus will now be front and center for weeks, which is not what he wanted,” said Mike DuHaime, a veteran GOP strategist.

“The more the focus is on Covid, the worse it is for him, because he wants this to be a referendum on the future, not on 2020,” DuHaime added.

The news caught many Trump aides by surprise and sent them scrambling to figure out how to proceed. By early Friday afternoon, Stepien released a statement saying that “all previously announced campaign events involving the president’s participation are in the process of being moved to virtual events or are being temporarily postponed.”

Stepien added that “previously announced events involving members of the first family are also being temporarily postponed,” and that “all other campaign events will be considered on a case-by-case basis.”

Pence would resume his schedule after testing negative earlier in the day, the campaign said.

But with time growing short, Trump aides conceded they're eager to get the president back into the public eye. Some suggested he go on television — perhaps with a national address — to discuss his diagnosis. But late Friday afternoon, that appeared unlikely, as Marine One was set to transport to Walter Reed hospital for treatment.

"I think it's important ... that the president be visible," said Mick Mulvaney, Trump's former chief of staff, in an interview on Fox Business on Friday. "That he be on the phone, that he be on television, that he gets out on the [White House] Truman Balcony, if he can, because it's important that people see him and know that he's there."

Perhaps the biggest question confronting Trump is the next debate, to be held Oct. 15 in Miami. After a widely panned performance in the first forum, he was intent on participating in the next one, Trump aides said. Officials with the Commission on Presidential Debates declined to comment on whether the event would be rescheduled or reformatted. And it's unclear now whether Trump will be physically able to participate.

Another major issue is fundraising. With the president facing a cash crunch, his team has been scheduling upcoming donor events in Los Angeles, Houston and Dallas. GOP officials said they were uncertain whether the fundraisers would go forward, or in what form.

Some senior Republicans said they were unsure why the president decided to attend a Thursday evening fundraiser at his Bedminster, N.J., golf club after being informed that senior aide Hope Hicks was experiencing symptoms.

“In-person political fundraisers are over for the foreseeable future. RIP. This is the nail in the coffin,” said Dan Eberhart, a Houston energy executive and Trump donor. “Trump should not have attended the fundraiser knowing Hope Hicks was sick and he had been in close proximity with her."

Others, however, disagreed, saying that none of the attendees were within eight feet of the president.

Organizers of the Bedminster event sent an email to attendees informing them of Trump’s diagnosis and encouraging them to “contact your medical provider if you or any of your loved ones is ill or develops a fever, shortness of breath, or other respiratory symptoms.”

Republicans stressed that some things would go forward as planned. The Republican National Committee — whose chairwoman, Ronna McDaniel, announced Friday that she too had contracted the coronavirus — is expected to proceed with its nationwide voter contact program. That includes a door-knocking effort in battleground states.

As they digested the news, Trump aides conceded they had little idea of how it would shift the race. Even before Friday, polls — including some conducted by Republicans — showed the president trailing across an array of battleground states.

But while Trump's diagnosis trains the spotlight on his biggest vulnerability — his handling of the pandemic — some Republicans saw a silver lining. Trump has long been dismissive of the virus, but this could allow the president to show empathy for other sickened Americans sickened.

“It does give him a chance to recast himself with his people and to show a thimbleful of humility,” said former George W. Bush White House aide Scott Jennings, “and to identify with what the rest of the people are going through.”

Caitlin Oprysko and Gabby Orr contributed to this report.