Barack Obama endorsed Joe Biden's White House bid on Tuesday, saying his longtime vice president can unify and "heal" a nation struggling through some of its darkest moments.
The formal backing by perhaps the most popular politician in America is the latest boost for Mr Biden's surging candidacy, and a further sign that Democratic leaders are rallying around the party flagbearer more than six months before November's election.
"Joe has the character and the experience to guide us through one of our darkest times and heal us through a long recovery," Obama said in a 12-minute video.
"I believe Joe has all the qualities we need in a president right now."
The cherished endorsement comes at a time of deep national anxiety, with the vast majority of Americans under stay-at-home orders due to the coronavirus pandemic that has killed nearly 25,000 people in the United States.
With President Donald Trump's handling of the outbreak under the spotlight, Obama signalled he believed Joe Biden -with four decades of government experience - would be a far more capable manager of the US response.
"Joe helped me manage H1N1 (influenza) and prevent the Ebola epidemic from becoming the type of pandemic we're seeing now," Obama said.
Mr Biden, 77, promptly expressed his thanks in a tweet.
"Barack - This endorsement means the world to Jill and me," the Democratic stalwart said.
"We're going to build on the progress we made together, and there's no one I'd rather have standing by my side."
Joe Biden is the Democratic Party's presumptive nominee to challenge Donald Trump, after his lone remaining opponent Bernie Sanders dropped out of the race last week.
The leftist US senator from Vermont endorsed his ex-rival Monday, saying it was time for Americans to "come together" behind Mr Biden.
Two-term president Barack Obama also praised Senator Sanders as a progressive champion whose energy and enthusiasm inspired young voters by the millions.
And he said it was time for those progressive supporters to help defeat the Republican incumbent.
"Right now, we need Americans of goodwill to unite in a great awakening against a politics that too often has been characterised by corruption, carelessness, self-dealing, disinformation, ignorance, and just plain meanness," Mr Obama said.
Barack Obama and Joe Biden wave to supporters during a campaign rally in September 2012. Source: EPA
"To change that, we need Americans of all political stripes to get involved in our politics and our public life like never before."
Special bond
Barack Obama's endorsement comes as the coronavirus has frozen traditional campaigning.
Typically, such high-profile support would be followed by Mr Obama's appearance at a major Joe Biden rally, generating substantial national coverage and prompting a deluge of campaign donations.
But it remains unclear when, if at all, on-the-ground campaigning will resume.
Mr Obama forged a special bond with Mr Biden during the eight years the former Delaware senator served as his wingman, awarding him the presidential medal of freedom in January 2017.
Barack Obama awarded Joe Biden the Presidential Medal of Freedom in January 2017. Source: EPA
But thus far in the 2020 race the nation's first African-American leader had largely flown under the political radar.
Despite his silence he was given a starring role in campaign advertisements by Joe Biden, Bernie Sanders and other candidates as they scrambled for advantage ahead of key primaries, such as those on Super Tuesday on March 3.
At campaign events and debates Mr Biden made sure to show he is running as Obama's heir, routinely highlighting the partnership with his former boss.
But Mr Biden, after sitting out 2016 to mourn the loss of his son Beau to cancer, had made clear from the start he would run on his terms.
"I asked president Obama not to endorse," he said last April 25, the day he launched his candidacy.
"Whoever wins this nomination should win it on their own merits."
