Leading Democrats are plotting a presidential campaign without Joe Biden leading the ticket.

The 81-year-old US President is under pressure to step aside and “pass the torch” to a younger candidate, following weeks of criticism from his own party regarding his mental faculties. 

Senior Democrats, including Chuck Schumer, the Senate Majority Leader, have indicated to party donors that they are actively planning their next steps in case Mr Biden decides to drop out, sources close to the matter told The Wall Street Journal.

Mr Schumer and former house speaker Nancy Pelosi have reportedly both told Mr Biden that his bid for reelection could endanger the party’s electoral chances in both chambers of Congress.

Now, top Democrats believe he could pull out as soon as this weekend after becoming “more receptive” to pleas for him to stand aside in recent days.

Allies of Kamala Harris are said to be quietly working behind the scenes to ensure that she is positioned to take the top spot on the ticket if Mr Biden does step down.

“Two or three days ago, people were quiet. And now, as of yesterday especially, people were like, ‘We need to be ready,’” one person involved in the discussion told Politico. “They are young in their infancy, but they have grown stronger by the hour.”

Ms Harris is now selling out donor events, including for a July 27 rally in Pittsfield, Massachusetts, where tickets cost between $100 and $12,000.

However, allies have acknowledged that scepticism remains within the party, including among senior Democrats, about her ability to win the presidency in a contest against former president Donald Trump.

Attacks are coming from Republicans who claim Ms Harris has not been honest about Mr Biden’s health and ability to lead.

A detailed report compiled by Democrats including voter surveys indicated that such assertions could damage Ms Harris’s ability to campaign.

The data, which forecast an Electoral College landslide loss, has caused alarm in the party’s leadership, leading to renewed calls both publicly and privately for the president to withdraw.

The data reveals that Mr Biden is not only trailing in all the swing states but is also behind or running neck-and-neck in traditionally Democratic states such as New Hampshire, Minnesota, New Mexico, Virginia and Maine. In New Jersey, he is leading by just 2.9 percentage points.

A total of 28 per cent of those who supported Mr Biden in 2020, along with 52 per cent of swing voters, believe that Democrats in office have been dishonest about the President’s mental health.

On Wednesday, Mr Biden tested positive for Covid-19 and is self-isolating at his home in Rehoboth Beach, Delaware, where allies hope he will have time to consider his position.

Kevin O’Connor, Mr Biden’s doctor, said on Thursday that the President’s symptoms were “mild” and that he had received a dose of Paxlovid, an antiviral medication.

According to the New York Times, Mr Biden has become more receptive to the idea that he may have to stand down.

US media reports said Mr Biden’s tone had changed behind closed doors, and he was now “willing to listen” to those making the case for him to end his campaign.

He has admitted that he “screwed up” in a disastrous television debate against Mr Trump on June 27 and that he does not “speak as smoothly as I used to”, but claims that concerns about his health are unfounded.

Some of Mr Biden’s closest allies at the top of the Democratic Party have begun to turn on him and now believe that he cannot beat Mr Trump.

As well as Mr Schumer, party grandee Ms Pelosi said Mr Biden looked likely to lose to Mr Trump and may cost his party their control of Congress if he remains in the race.

On Thursday, Barack Obama, the former president, became the latest senior figure to express concerns about his age.

He told several allies he was worried about Mr Biden’s poll ratings and believes he should seriously consider standing down to protect the party and his legacy, according to multiple reports in US media outlets.

Mr Biden is said to be personally hurt and betrayed by the number of leading Democrats who have turned against him, with sources telling NBC that he feels angry at how the party has tried to push him 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? In 2015, Obama, Pelosi, and Schumer pushed Biden aside in favour of Hillary; they were wrong then, and they are wrong now,” the source said.

More than 20 sitting Democrats have gone public with their concerns, while donors have suspended contributions to Mr Biden’s campaign and celebrity backers including George Clooney have called for him to leave the race.

New York Representative Alexandria Ocasio-Cortez chimed in on Friday morning, warning that many of those calling for Mr Biden to exit the race also want Ms Harris removed from the ticket.

“If you think that there is consensus among the people who want Joe Biden to leave… that they will support Vice President Harris, you would be mistaken,” she said.

She added that Democratic leaders needed to be “fully honest” with voters. “If they’re going to come out and say all their little things on background, off the record, but they’re not going to be fully honest, I’m going to be honest for them. I’m in these rooms. I see what they say in conversations,” Ms Ocasio-Cortez said.