by Gareth Evans, Courtney Subramanian, Kayla Epstein, BBC News, Washington & New York

US President Joe Biden on Wednesday sought to calm Democratic campaign officials and staff amid reports that he was pondering his future after his disastrous debate defeat against President Donald Trump.
Biden held a private lunch with Vice President Harris at the White House amid growing speculation about whether she will replace Biden as the party’s nominee in the November election.
The two then took part in a conference call with the entire Democratic campaign, in which Biden made clear his intention to remain in the race and Harris reiterated her support. “I’m the Democratic nominee. Nobody’s trying to get rid of me. I’m not leaving the party,” Biden said on the call, a source told BBC News.
The same phrase was repeated in a fundraising email sent by the Biden-Harris campaign a few hours later. “Let me say this as clearly and simply as possible: I am running,” Biden said in the email, adding that he would “run this campaign to the end.”
Trump’s stammering, weak voice and inaudible responses during the debate have raised questions about whether the 81-year-old Trump will continue campaigning, raising concerns among Democrats about his fitness to run and whether he can win the election.
Since then, pressure on Biden to back down has only intensified as more polls show his Republican rival’s lead growing. A New York Times poll conducted after the debate and released on Wednesday suggested Trump now holds a 6-point lead, his largest to date.
A separate poll published by the BBC’s US partner CBS News suggested Mr Trump had a three-point lead over Mr Biden in key battleground states, and the survey also showed the former president leading nationally.
His unfavorable polling position has been exacerbated by public calls from some Democratic donors and lawmakers for the president to step aside. Ramesh Kapoor, a Massachusetts-based Indian-American businessman who has been organizing Democratic fundraisers since 1988, is one such example.
“I think it’s time for him to hand over the baton,” Kapoor told the BBC. “I know he has the drive, but you can’t fight Mother Nature.”
Two Democrats in the House of Representatives have also called for replacing the party’s top candidate, with the latest, Rep. Raul Grijalva of Arizona, telling The New York Times that it’s time for Democrats to “look elsewhere.”
Nevertheless, the White House and Biden’s campaign have strongly denied reports that Biden is actively considering his future and say he is determined to defeat Trump again on November 5th.
The New York Times and CNN reported Wednesday that Biden told unnamed allies he was considering whether to continue in the campaign.
According to both reports, the president told allies he knows his reelection is in jeopardy and that upcoming activities, such as the ABC News interview and Friday’s rally in Wisconsin, are crucial to the campaign.
Shortly before White House press secretary Karine Jean-Pierre was bombarded with questions about Biden’s election efforts, she denied the reports as “categorically false.”
She said reports that he might back out were not true. “We have asked the president. [and] The president responded directly and said, ‘No, that’s completely false.’ That’s something he said directly to me.”
During a conference call with White House staff on Wednesday, Chief of Staff Jeff Zients urged staff to “keep their heads down,” according to CBS News.
“Get things done. Run. Run. Run,” he said.
“There is much to be proud of, and much more we can do together under the president’s leadership.”
Biden met late Wednesday with 20 Democratic governors from around the country, including California’s Gavin Newsom and Michigan’s Gretchen Whitmer, both of whom are seen as potential successors to Biden if he steps down.
“The president has always had our backs, and we’re going to have our backs,” Maryland Gov. Wes Moore told reporters after the meeting.
New York Gov. Kathy Hauckle said 24 governors who had just met with the president had voiced their support and that Biden had vowed to “fight to win.”
But Harris remains seen as the most likely successor. The 59-year-old is hampered by low approval ratings, but her support among Democrats has grown since the Biden-Trump debate.
The vice president gave an interview to CNN immediately after the debate, in which he calmly expressed his full support for the president.
“She hasn’t changed anything,” a source close to Ms Harris told BBC News, adding that she would continue to work for the campaign.
“She has always tried to be a good partner to the president,” said Jamal Simmons, Ms. Harris’ former communications director.
“The people who ultimately make the decision on who should be the nominee are those who are primarily loyal to him. Her best role is to be his partner.”
Members of the Democratic National Committee are responsible for casting the votes at the party’s convention in August to formally select Biden as the party’s nominee and place him on ballots across the country.
Speaking to other delegates, one member, who requested anonymity to speak candidly about a sensitive discussion, told the BBC that Vice President Harris should be the nominee if Biden does not run.
“If we were to resume the tournament it would cause total chaos that would cost us in November,” they said.
Meanwhile, The Washington Post reports that Biden and his team know they must prove their fitness to be president in the coming days.
He will attend the Medal of Honor ceremony on Wednesday and has plans to travel to Wisconsin and Philadelphia later this week.
Adam Levy and Brajesh Upadhyay contributed to this report.