Despite weeks of crisis talks and dozens of Democrats calling for him to step down, Joe Biden’s Sunday decision to withdraw still managed to take America – and most White House and campaign staffers – by surprise.

The 81-year-old president was isolating with COVID at his $3.4 million holiday home in Rehoboth Beach, Delaware, when his shrinking inner circle handed him polling data showing he could no longer beat Donald Trump after his train-wreck debate performance over three weeks ago and the poor handling of its aftermath, sources have confirmed.

That was when they were finally able to convince a reportedly angry Biden to draft a letter saying it was time for him to step aside for the good of the Democratic Party with donors pulling millions of dollars in pledged funds and the list of elected Democrats telling him to drop growing by the minute.

Jill Biden was by her husband’s side when he eventually made the historic call, giving into mounting pressure. But a spokeswoman for the First Lady said it was the president’s judgment alone, and confirmed he made it late.

‘Down to the last hours of the decision only he could make, she (Jill Biden) was supportive of whatever road he chose,’ the spokeswoman said. ‘She’s his biggest believer, champion, and always on his side, in that trusted way only a spouse of almost 50 years can be.’

Here’s how a seemingly foregone conclusion somehow managed to stun the nation:

On Saturday evening, Biden summoned to his side two men who have been there since his political start: advisers Steve Ricchetti and Mike Donilon.

They have been with him through the best of times – his first years as a senator – and the worst of times – the death of his son Beau Biden in 2015.

Already with the president and the first lady were their closest aides Annie Tomasini and Anthony Bernal, who they refer to as ‘family.’

It was Ricchetti and Donilon who brought with them devastating new data which would help to make up Biden’s mind.

They revealed the latest internal campaign polling, taken since the debate, which showed he could no longer beat Trump.

Biden’s decision was made soon after, and he asked Ricchetti and Donilon to start drafting a letter, and to begin the process of how to make a public announcement, DailyMail.com confirmed. The president also began telling his family.

Biden had previously insisted that he would only step aside if he was shown polling that proved Kamala Harris would fare better than him against Trump, or if he developed a ‘medical condition’. In the end, it was the first of those developments that sealed his fate.

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