A third senator, Ron Johnson, Republican of Wisconsin, has tested positive for the coronavirus this week, his office said in a statement Saturday morning, raising further questions about whether Republicans’ extraordinarily ambitious timetable to confirm Judge Amy Coney Barrett to the Supreme Court could hold.
Mr. Johnson, the chairman of the Senate homeland security committee, was exposed to an individual earlier in the week who tested positive for the virus, according to his office, which said the senator was “not experiencing symptoms.” He did not attend President Trump’s nomination ceremony for Judge Barrett at the Rose Garden on Saturday.
Unlike Senators Thom Tillis of North Carolina and Mike Lee of Utah, who tested positive on Friday, Mr. Johnson does not sit on the Senate Judiciary Committee. But his positive test result adds new complications to the timing of Judge Barrett’s confirmation.
Top Senate Democrats demanded on Friday that Republicans slow their plans for confirming Judge Barrett, saying that if Republicans were to proceed with hearings without an understanding of the full extent of the virus’s spread from the Sept. 26 events, an “already illegitimate process will become a dangerous one.”
The Sept. 26 Rose Garden ceremony for Judge Barrett was most likely not a “super-spreader” event, because it was outdoors. However, many top Republicans attended without masks or social distancing, raising concerns that others might have contracted the virus but had not yet been diagnosed. And someone who was infected and did not have symptoms could have transmitted the virus to others during indoor discussions inside the White House.
But leading Republicans have said they planned to continue “full steam ahead” to confirm Judge Barrett before Election Day.
Senator Lindsey Graham of South Carolina, the Judiciary Committee chairman, said on Friday that his panel would begin four days of public hearings on Judge Barrett’s nomination on Oct. 12, as scheduled. Mr. Tillis and Mr. Lee said they would isolate for 10 days, which would enable them to emerge in time for the hearings.
And in an interview on Friday, Senator Mitch McConnell of Kentucky, the majority leader, suggested that the virus’s spread through Republican circles could mean that more lawmakers would participate in the hearings virtually. “This sort of underscores the need to do that,” he said.
But Democrats said that virtual hearings on such a consequential matter would be unacceptable.
Republicans hold a narrow majority in the Senate, meaning they can only afford to lose three votes in their push to confirm her. Two Republicans, Senators Lisa Murkowski of Alaska and Susan Collins of Maine have said they would not confirm a nominee before the election.
Since March, some of President Trump’s advisers had whispered that there could come a day when the president tested positive for the coronavirus. But it was not an eventuality anyone planned for.
When the day came, early Friday morning, it upended the presidential campaign, and left unanswered questions in its wake.
Mr. Trump is currently at the Walter Reed National Military Medical Center in Bethesda, Md., where officials said he will be monitored for “a few days,” strictly as a precaution.
But one official said that having Mr. Trump leave the White House on his own was preferable to the possibility of being removed with assistance should his symptoms get worse — and his walk to Marine One, the presidential helicopter, which transported him to the hospital, allowed him to be seen, ambulatory, by reporters after a day during which the ubiquitous president was silent.
What happens next is anyone’s guess. Trump advisers hope that he can quickly recuperate and show what one called “resolve” in the face of a virus that has caused a pandemic.
But the second debate between Mr. Trump and former Vice President Joseph R. Biden Jr. is scheduled for Oct. 15, a relatively short time in the life of recovery from the coronavirus.
For now, the reversal of fortune — in which Mr. Biden is out on the campaign trail, and the president, who used to mock his opponent, is out of sight — weighed heavily on the Trump campaign.
Former President Barack Obama and Senator Kamala Harris of California offered their prayers to President Trump and the first lady, Melania Trump, on Friday evening, colliding with the timing of an emailed fund-raising appeal from the Trump campaign.
The subject line: “Lyin’ Obama.”
“Lyin’ Obama and Phony Kamala Harris are calling up their Liberal MEGA DONORS to come and rescue Joe Biden’s failing campaign,” read the message. “They’re holding a COASTAL ELITE fund-raiser RIGHT NOW.”
Just minutes earlier, Mr. Obama and Ms. Harris, the Democratic nominee for vice president, had opened their virtual fund-raiser by wishing the president and his wife a speedy recovery, with the former president urging all Americans to hope for the president’s recovery even in the middle of a contentious campaign.
The combative tone of the email came hours after the Biden campaign pulled down all its negative ads against the president, though some already in circulation could take time to stop airing.
The Trump campaign has announced no plans to stop its attack ads against the Democratic nominee.
During the online fund-raiser for former Vice President Joseph R. Biden Jr., Mr. Obama told watchers: “Even when we’re in the midst of big political battles with issues that have a lot at stake, that we’re all Americans and we’re all human beings, and we want to make sure everybody is healthy. Michelle and I want to make sure we acknowledge the president and the first lady at this difficult time.”
Ms. Harris offered her “deepest prayers,” adding, “Let it be a reminder to all of us that we must remain vigilant and take care of ourselves and take care of each other.”
The two officials, who were joined by the actor Michael B. Jordan, also tried to assuage concerns and dispel misinformation about voting, particularly casting ballots by mail. Mr. Trump has spent weeks waging a disinformation campaign about the integrity of the American electoral system.
All three said they planned to cast their ballots by mail.
“I’m going to fill it out at my kitchen table and I’m going to get over to the drop box and I’m going to drop it off as early as I can,” said Ms. Harris, who added she had the date to request her ballot circled on her calendar.
Mr. Obama, who rattled off the name of his polling place in Hyde Park, Ill., said he had cast mail-in ballots since winning the presidency, in part to avoid the crowds that slow down lines when he appears.
“When I vote in person, there’s a price,” he said. “It slows down a whole bunch of folks.”
President Trump’s bombshell announcement early Friday morning that he and the first lady had tested positive for the coronavirus has set off a frenzy in the White House and beyond as politicians and operatives who have interacted with Mr. Trump in recent days have raced to get their own tests and, in some cases, report the results.
Here is a quick look at the people in Mr. Trump’s orbit and beyond who have spoken publicly on Thursday and Friday about their health and the virus, taken from official statements, announcements made on social media, and spokespeople.
It can take several days after exposure for the virus to reach levels that are detectable by a test. People show symptoms on average around five days after exposure, but as late as 14 days.
Who has tested positive:
Ronna McDaniel, the chairwoman of the Republican National Committee
Hope Hicks, one of Mr. Trump’s most senior advisers
Bill Stepien, President Trump’s campaign manager
Kellyanne Conway, the former top White House adviser, who attended Judge Amy Coney Barrett’s Supreme Court nomination ceremony at the White House on Sept. 26
Senator Thom Tillis of North Carolina, who participated in a debate against his Democratic challenger on Thursday
Rev. John I. Jenkins, the president of the University of Notre Dame, who also attended the ceremony for Judge Barrett last week
Senator Ron Johnson of Wisconsin, he did not attend Judge Barrett’s ceremony last week
Chris Christie, the former governor of New Jersey
Who has tested negative:
Mike Pompeo, the secretary of state
Steven Mnuchin, the Treasury secretary
William P. Barr, the attorney general
Mark Meadows, the White House chief of staff
Dan Scavino, the White House deputy chief of staff
Jared Kushner, Mr. Trump’s son-in-law and senior adviser
Ivanka Trump, Mr. Trump’s daughter
Donald Trump Jr., Mr. Trump’s son
Barron Trump, Mr. Trump’s son
Eric Trump, Mr. Trump’s son
Lara Trump, Eric Trump’s wife
Tom Perez, the chairman of the Democratic National Committee
Betsy DeVos, the education secretary
Cal Cunningham, the Democratic former state senator and Iraq war veteran who is locked in a closely watched and tight race to unseat Senator Thom Tillis of North Carolina, a Republican, apologized on Saturday after a report that he had exchanged romantic text messages with a woman who is not his wife.
Screenshots of some of the text messages first emerged on Thursday; the Cunningham campaign confirmed their authenticity on Saturday morning. In the messages, Mr. Cunningham, who is married and a father of two teenagers, calls the woman “historically sexy,” the two discuss kissing each other and Mr. Cunningham says he had dreamed about his time with the woman.
It is not clear when exactly the messages were exchanged, but they allude to “crazier fall schedules” and Mr. Cunningham writes that he is “nervous about the next 100 days.”
“I have hurt my family, disappointed my friends and am deeply sorry,” Mr. Cunningham said in a statement on Saturday morning. “The first step in repairing those relationships is taking complete responsibility, which I do.”
Mr. Cunningham added that he was humbled and grateful for the support he is receiving from North Carolinians, and that he would “continue to work to earn the opportunity to fight for the people of our state.”
The revelation about Mr. Cunningham’s exchanges comes roughly a month before Election Day and adds a new element of uncertainty into a critical race that had already been thrown into disarray on Friday, when Mr. Tillis announced that he had tested positive for the coronavirus and would quarantine at home for 10 days. In a statement, Mr. Tillis said he had “no symptoms” and felt “well.”
Mr. Cunningham said he would get tested after debating Mr. Tillis a day earlier, and wished the senator a “quick recovery.”
North Carolina is critical battleground state that Democrats have long eyed as they seek to pick up multiple seats in the Senate and wrest control of the chamber from Republicans. A New York Times/Siena College poll last month showed Mr. Cunningham leading the race by five percentage points.
Democrats are likely to lose one Senate seat they currently hold in Alabama, where Senator Doug Jones is a long shot. If Mr. Jones were to lose, they would need to secure four seats currently held by Republicans to get to 50, which would give control of the Senate if Joseph R. Biden Jr. is elected president and his running mate, Senator Kamala Harris, could break ties in the chamber.
Democrats appear to be within range of that goal, as polling has shown their candidates leading in Senate races in Arizona, Maine and Colorado, in addition to North Carolina. Democratic candidates are also competing aggressively in other Senate contests in states President Trump won handily in 2016, including places like Iowa and South Carolina.
President Trump’s positive coronavirus test has raised the possibility, however remote, that he could become incapacitated or potentially die in office if his symptoms worsened.
While that outcome remains highly unlikely, and few in Washington were willing to discuss it on Friday, the Constitution and Congress long ago put in place a plan of succession.
The Constitution makes clear that the vice president is first in line to succeed the president should he or she die in office, and can step in to temporarily take on the duties of the presidency should the commander in chief become incapacitated. Vice President Mike Pence, 61, tested negative for the coronavirus on Friday.
The ascension of a vice president under such circumstances has not been that rare in American history. Eight times a vice president has assumed the nation’s highest office because of the president’s death, most recently in 1963, after the assassination of John F. Kennedy, when Lyndon B. Johnson became president. In 1974, Vice President Gerald Ford became president upon the resignation of President Richard M. Nixon.
The Constitution leaves it to Congress to decide what would happen if the vice president also died or was unable to perform the duties of the presidency. Congress has passed several laws over the years. The Presidential Succession Act was enacted in 1947 after the death of President Franklin D. Roosevelt. (It was tweaked again in 2006.) The statute states that the speaker of the House is next in line, followed by the president pro tempore of the Senate, and then members of the cabinet, starting with the secretary of state.
Speaker Nancy Pelosi, 80, said on Friday that she had been tested for the virus out of an “abundance of caution,” and a spokesman later revealed she tested negative.
Senator Charles E. Grassley, Republican of Iowa, is the current president pro tempore in the Senate. He is 87.
A White House spokesman said Friday that Mr. Trump had not transferred power to Mr. Pence.
“No transfer,” said the spokesman, Judd Deere. “The president is in charge.”