It wasn’t the address Joe Biden had envisaged.

A few short weeks ago, the US president planned to gild his re-election bid before rapturous Democrats at the party’s convention in Chicago.

It was due to be his first time accepting a presidential nomination before a live audience after decades spent pursuing the White House.

In 2020, the Covid-19 pandemic had robbed him of his crowning moment. In 2024, it was his own party.

Alarmed by his performance and his polls, Democrats had forced Mr Biden to follow through on his one-time promise to serve as a “bridge” to a new generation.

Before he passed the baton on to Kamala Harris, Mr Biden felt he should remind Democrats, and Americans watching at home, of the extent of his legacy.

His presidency, he argued, had seen “the most extraordinary four years of progress”.

It had been the “honour of a lifetime” to serve in the Oval Office, he told the crowd.

But fate, a powerful force in his half a century spent in politics, appeared to have intervened once again.

“Let me know in my heart when my days are through,” he quoted from a favourite song.

He wryly noted he was dismissed as a 29-year-old senator for being too young. Now, at 81, he was deemed “too old” to remain president.

Nevertheless he rejected claims he was “angry at all those people who said I should step down” – many of whom were sitting in the audience before him.

“I love the job, but I love my country more,” he said.

Instead, his rage was directed instead towards Donald Trump.

The fire and energy in Mr Biden’s speech was in stark contrast to the version of the president Americans watched struggling on the debate stage less than two months ago.

He argued the Republican candidate had bowed “down to Putin”, left Nato “in tatters” and was “not worthy of being commander-in-chief”.

Yet Mr Biden, a man who has spent most of his political life running for president, acknowledged it was now down to another to attempt to block Trump’s return.

Bidding farewell to his party, and his country, he said: “America, I gave my best to you”.

Mr Biden has planned a swift departure from the convention, heading for a two-week holiday with his family rather than watching his party crown his successor.

In exiting the stage, he hands the national spotlight to his vice president, but promised to be “the best volunteer” for her White House bid.

“Selecting Kamala was the very first decision I made when I became a nominee and it was the best decision I made in my whole career,” he said.

Breaking into a smile, he joked: “Like many of our best presidents, she was also vice president”.

More than once, the audience broke into chants of “thank you, Joe”.

But there was a double meaning to the words. They were thankful for his years of service, but even more so for his departure.