Former President Barack Obama endorsed Joseph R. Biden Jr. on Tuesday, casting him as the steady leader the country needed to combat the coronavirus pandemic and continuing the unification of Democratic leaders around the party’s presumptive presidential nominee.
Mr. Obama’s endorsement of his former vice president, in a video released on Tuesday, came just one day after Senator Bernie Sanders of Vermont, who had been Mr. Biden’s last challenger, also endorsed him, and Mr. Obama’s remarks included direct appeals to the supporters of Mr. Sanders.
“If there’s one thing we’ve learned as a country from moments of great crisis, it’s that the spirit of looking out for each other can’t be restricted to our homes or our workplaces or our neighborhoods or our houses of worship,” he said in his endorsement video.
“It also has to be reflected in our national government,” he said. “The kind of leadership that’s guided by knowledge and experience, honesty and humility, empathy and grace — that kind of leadership doesn’t just belong in our state capitals and mayor’s offices. It belongs in the White House. That’s why I’m so proud to endorse Joe Biden for president of the United States.”
The former president is perhaps the most influential figure in Democratic politics, and his active support could play a critical role in energizing and coalescing the party around Mr. Biden, who still faces skepticism from younger and more progressive voters.
While the Democratic race was competitive, Mr. Obama remained publicly neutral and offered advice to all comers, even as multiple candidates tried to link themselves to him. But now, with the primary effectively over, attention is turning to the potentially difficult task of unifying the party for the general election — and Mr. Obama is uniquely positioned to help do that.
Behind the scenes, he has been involved for some time and played a key role in persuading Mr. Sanders to end his campaign and endorse Mr. Biden.
Over the past several weeks, he reached out to Mr. Sanders on at least four occasions to reassure him that he had already achieved his goal of moving the Democratic Party to the left, according to people with direct knowledge of their exchanges.
At the same time, Mr. Obama began discussing the terms of his engagement on behalf of Mr. Biden, counseling caution even as Biden aides and party officials pressed him to help them bolster their lagging fund-raising operations immediately.
Mr. Obama’s announcement was timed to follow Mr. Sanders’s endorsement on Monday, and both were delayed for a few days by the Passover and Easter holidays — contrary to Mr. Trump’s false claim that Mr. Obama was having second thoughts.
Mr. Biden, while relieved to have Mr. Obama’s help, is also intensely proud of his own comeback — from fourth- and fifth- place finishes in Iowa and New Hampshire to his perch as the presumptive nominee.
Still, on the campaign trail, Mr. Biden referenced his work with Mr. Obama constantly, and many voters ultimately said they were comfortable with Mr. Biden because they saw him as a familiar figure who could restore the perceived predictability and stability of the Obama era. His association with the nation’s first black president was a factor in the strong support Mr. Biden received from many African-American voters during the primary.
Mr. Biden spoke frequently about the strong partnership the two men had in the White House, making clear that he would want a similar dynamic with his future running mate. He and Mr. Obama have discussed how the former president conducted his vice-presidential search process, and the importance of selecting a partner with experience.
“The most important thing, and I’ve actually talked to Barack about this — the most important thing is that there has to be someone who, the day after they’re picked, is prepared to be president of the United States of America if something happened,” Mr. Biden said at a fund-raiser last month.
Glenn Thrush contributed reporting.