As President Joe Biden isolated at his beach house in Rehoboth, Delaware, on Thursday after testing positive for Covid, he faced renewed pressure from leading Democrats to drop out of the 2024 election contest against former President Donald Trump.

Biden, who for weeks has flatly rejected calls to step aside and allow another nominee to take his place, is now said to be more open to listening to top Democrats about the risk of him remaining in the race. He has also reportedly asked advisers in recent days whether they believe his vice president, Kamala Harris, could beat Trump in November.

“We’re close to the end,” a person close to Biden told NBC News.

The pressure on the 81-year-old Biden stems from concerns that after his June 27 debate, if he remains the nominee he will not only cost Democrats the White House, but also cost the party its majority in the Senate and doom its chances of retaking the House.

Former President Barack Obama has privately expressed concerns to Democrats about the viability of Biden’s candidacy, both the Associated Press and The Washington Post reported.

Biden served two terms as Obama’s vice president, and the 44th president still has unrivaled influence within the Democratic party.

The two Democratic leaders in Congress — Senate Majority Leader Chuck Schumer and House Minority Leader Rep. Hakeem Jeffries, both of New York — have told Biden in recent days that his presence on the party ticket could cost them majorities in both chambers of Congress.

Sen. John Hickenlooper, D-Colo., told the Reuters news service late Wednesday that Biden is “working towards” a decision that will “put the country first.” Hickenlooper did not explicitly call on Biden to drop out, saying that was “his decision to make.”

“But certainly there’s more and more indications that that would be in the best interests of the country, I think,” the senator said.

Rep. Adam Schiff of California, the Democratic nominee for one of the state’s two Senate seats, openly called for Biden to drop out of the race Wednesday.

Schiff and Hickenlooper joined about 20 other Democrats in Congress who have made similar public calls.

Schiff is close to Rep. Nancy Pelosi of California, the Democratic former House speaker. CNN reported Thursday morning that Pelosi told Biden recently that he cannot beat Trump and that he could doom Democratic chances of winning a House majority if he insists on remaining in the race.

Sen. Bob Casey, a Pennsylvania Democrat who to date has fully supported Biden’s plan to stay in the race, told NBC News on Thursday he had heard “growing concerns” from voters in his state this week.

“I’ve talked to a lot of people in our state that have concerns ever since the debate,” Casey said. “But I think my position has been very clear, and I think I think the president will do what he’s always done, which is put the best interests of the country first.”

The Biden campaign’s public response to growing concerns has not changed, and top staffers remain dead-set against the president dropping out.

“Our campaign is not working through any scenarios where President Biden is not the top of the ticket,” Quentin Fulks, principal deputy campaign manager told reporters in Milwaukee on Thursday.

“He is and will be the Democratic nominee,” said Fulks.

Later Thursday, a source close to Biden pushed back at the top Democrats pressuring for the president to bow out.

“Can we all just remember for a minute that these same people who are trying to push Joe Biden out are the same people who literally gave us all Donald Trump?” the source told NBC News.

“In 2015, Obama, Pelosi, Schumer pushed Biden aside in favor of Hillary; they were wrong then and they are wrong now,” the source said.

That source also noted how polls in 2016 showed the Democratic Party’s presidential nominee Hillary Clinton leading Trump by as much as 9 percentage points.

“How did all this work out for everyone in 2016?” the source said, referring to Trump’s victory that year.

“Perhaps we should learn a few lessons from 2016; one of them is polls are BS, just ask Sec. Clinton. And two, maybe, just maybe, Joe Biden is more in touch with actual Americans than Obama-Pelosi-Schumer?” the source added.