WASHINGTON (CN) — Former President Barack Obama endorsed Joe Biden for the nation’s highest office Tuesday, saying his vice president is the best candidate to lead America through these unprecedented times.

“Joe has the character and experience to guide us through one of our darkest times and heal us through a long recovery,” said Obama, who delivered his endorsement, without a tie, in a video posted to YouTube.

Obama specifically discussed Biden for only about three minutes of the 12-minute video, assuring the public that his former veep would lead with “knowledge and experience, honesty and humility, empathy and grace.”

“I’m so proud to endorse Joe Biden for president of the United States,” Obama said. “Choosing Joe to be my vice president was one of the best decisions I ever made.”

The video message followed one day after Biden was endorsed by his longest-lasting opponent on the campaign trail, Vermont Senator Bernie Sanders.

While the Sanders endorsement amounted to a capitulation of sorts by the Democratic Party’s progressive wing, Obama is highly popular throughout the party and his move may serve to unify Democrats after an at-times fractious primary battle.

Obama began his speech with a two-minute focus on the novel coronavirus that has sickened nearly 2 million around the world and at least half a million in every corner of the United States. He said Biden’s involvement in handling the H1N1 and Ebola viruses, as well as rebuilding the economy after the 2008 financial crash, made him well-suited to lead America through the pandemic.

In addition to speaking about Covid-19, Obama also heaped praise on Sanders. “Bernie’s an American original, a man who has devoted his life to giving voice to working people’s hopes, dreams, and frustrations,” Obama said. “He and I haven’t always agreed on everything, but we’ve always shared a conviction that we have to make America a fairer, more just, more equitable society.”

Obama then attempted to persuade progressives to change their allegiance from Sanders to Biden.

Biden “already has what is the most progressive platform of any major-party nominee in history,” Obama argued, saying it would bring “real structural change” to America.

“If I were running today, I wouldn’t run the same race or have the same platform as I did in 2008. The world is different,” he added. “We have to look to the future.”

The second half of the video was an attempt to rally support for the party’s themes in general. Obama praised the health care law that had been the signature achievement of his administration but said it was “time to go further” with a public option and an expansion of Medicare.

He accused Republicans of “just plain meanness.”

Today’s endorsement today is likely to put to rest a Republican line of attack suggesting that the former president didn’t endorse his second-in-command because of doubts about his abilities.

Obama has kept a low profile throughout the Democratic primaries. In 2016 he didn’t endorse his former secretary of state, Hillary Clinton, until she had officially won the nomination in a race against Sanders.

But while Obama didn’t endorse Biden during the primaries, Biden did his best to tie himself to his old boss, often referring to himself as an “Obama-Biden Democrat.”

President Trump’s campaign manager Brad Parscale downplayed the endorsement. “Barack Obama spent much of the last five years urging Joe Biden not to run for president out of fear that he would embarrass himself,” Parscale said in a statement released by the campaign. “Now that Biden is the only candidate left in the Democrat field, Obama has no other choice but to support him.”

Overshadowed by the other events of the week was the fact that official results showed Biden won the Wisconsin primary over Sanders by a margin of 63% to 32%.