President Joe Biden's legacy rested on Vice President Kamala Harris's success in the election
President Joe Biden's legacy rested on Vice President Kamala Harris's success in the election AFP

Joe Biden hoped Kamala Harris would salvage his legacy as the man who saved America from Donald Trump. Instead, it lies in tatters.

The 81-year-old's pride made him resist growing concerns about his age, health and mental acuity until it was too late, and a disastrous debate against Trump forced him to drop his bid for a second term barely three months before Election Day.

Biden cast the decision as a move to "pass the torch" to a new generation of leadership in the form of his vice president, whom he endorsed as the new Democratic nominee.

Had Harris won, the rows over his age and refusal to bow out earlier would have been forgiven by the Democratic Party.

Biden would have been able to celebrate a list of achievements in his one term that included guiding the country out of the Covid crisis, passing historic legislation, building infrastructure and promoting green energy.

On the foreign front he helped Ukraine's fight against Russia's invasion and hoped, against hope, that he could still end Israel's conflict in Gaza.

US presidents famously always have an eye on the way they will be judged by history, and it was therefore in his interest that Harris should win against Trump.

Harris was "very much a legacy project," for Biden, said Frank Sesno, a professor at George Washington University and former White House correspondent.

But Democrats are now likely to judge Biden far more harshly.

His bid for a second term was "perhaps a little bit of arrogance, or over-reaching," Alex Keena, an associate professor of political science at Virginia Commonwealth University, told AFP.

Back in 2020 Biden had run on a promise to be a transitional president, but his decision to seek four more years meant that when he dropped out there was no time for a proper primary to find a replacement.

"It was a missed opportunity for the Democrats to nominate someone with broad appeal," said Keena.

"Granted, they might have nominated Kamala Harris... but as a result, the country didn't get a chance to really know Kamala Harris or see her fight for the Democratic base."

In fact Biden had convinced himself that having beaten Trump once, he was the only man who could beat him again.

It was in character for a proud and often stubborn man who loved to cite his family's mantra that "when you get knocked down, get back up again."

From playground punch-ups to a stutter to the terrible tragedy of losing his wife and baby daughter in a car crash, Biden had long seen his life as a series of comebacks against impossible odds.

Biden even said Trump's first term was an "aberration."

But now it is Trump making the comeback -- and it is Biden's single term in office that will be the outlier between two Trump terms.

Biden's remaining two and a half months in office will see him try to salvage what he can of the legacy he craves.

The Democrat began the effort within hours of Trump's victory, reaching out to invite him to the White House and promising a peaceful transition of power -- a stark contrast to the Republican's unprecedented refusal to do the same when he lost to Biden.

He will address the nation on Thursday to "discuss the election results and the transition," the White House said.

Biden is seeking to seize the moral high ground over a man who not only wouldn't accept the 2020 election result, but tried to hold onto power, stymied the transition process and refused to attend the incoming Democrat's inauguration.

But it won't come easy.

"That's got to be a terrible feeling," said Keena, adding that Biden would have to "make a decision about how cordial he is."

Biden will also know that Trump is likely to immediately set about dismantling key parts of his achievements, from green energy to his backing of Ukraine.

"Knowing that Trump is going to try very hard to undo his legacy, it has to be that has to be a terrible way to go out for somebody who's served for so many years in public service," Keena added.