Sen. Bernie Sanders' presidential campaign released a new advertisement featuring Sanders and President Barack Obama side by side, in which Obama can be heard praising Sanders and saying "Feel the Bern!"

Former Mayor Mike Bloomberg of New York City, who dropped out of the race Wednesday, also previously made ads implying Obama supported him. Obama has not endorsed any candidate in the 2020 Democratic presidential primary.

The ad was met with confusion and criticism by the Biden campaign, former Obama officials, and journalists. Sanders "wasn't particularly close" with Obama, the former Obama adviser David Axelrod tweeted.

Sanders appears to be taking on former Vice President Joe Biden, who is ascendant after a night of Super Tuesday wins.

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Former President Barack Obama has not endorsed any candidate in the 2020 Democratic presidential primary, but a new ad released by Sen. Bernie Sanders of Vermont is made to look as if Obama is feeling the Bern.

Hours after Joe Biden, Obama's vice president, staged a surprise comeback to claim 10 Super Tuesday states, including Virginia and North Carolina, the Sanders campaign released an ad featuring Sanders and Obama walking side by side through the White House and laughing together.

Sanders is not the first candidate to cut such an ad. Before dropping out of the race, former Mayor Mike Bloomberg of New York City drew criticism from several former Obama aides after he released a similar ad that appeared to imply Obama had endorsed him when he did not.

But Sanders has long positioned himself as an antiestablishment candidate, and his vows to take on the Washington elite have won him a fervent base of supporters. The campaign's decision to release an ad placing him alongside the figurehead of the Democratic Party was met with confusion by journalists and a prominent Obama aide and derision from Biden staffers.

"The day after a very tough day in which black voters broke heavily against him, @BernieSanders surfaces ad featuring past praise from @BarackObama, with whom he wasn't particularly close," the former Obama senior adviser David Axelrod tweeted.

Biden's rapid-response director, Andrew Bates, told Insider in a statement: "Barack Obama chose Vice President Biden to be his partner over 8 years in the White House ... By contrast, Senator Sanders explored a primary challenge to President Obama," a reference to a report in The Atlantic that Sanders has denied.

"No quantity of ads can rewrite history," Bates said.

On Twitter, Bates replied to a reporter who questioned the logic of the ad with a snarky upside-down smiling emoji. Meanwhile, reporters scratched their heads about Sanders' latest play.

The ad appeared to be part of a strategy focused on hitting Biden, who is on the ascent and is now Sanders' chief rival for the Democratic nomination. The Sanders campaign also released two other ads, one hitting Biden for his support of the North American Free Trade Agreement and another claiming Biden wants to cut Social Security.

"Bernie is somebody who has the virtue of saying exactly what he believes," Obama says in a voiceover. "Great authenticity, great passion, and is fearless."

"People are ready for a call to action," Obama's voice is heard saying. "They want honest leadership who cares about them ... they want somebody who's going to find for them ... and they will find it in Bernie."

The spot ends with a brief clip of Obama speaking at the 2016 Democratic National Convention, in which Hillary Clinton won the nomination over Sanders. "Feel the Bern!" Obama said.

The voiceover actually spliced together several Obama speeches and interviews, CNN's Daniel Dale pointed out, including a 2016 interview with Politico and Obama's DNC speech, where he was actually attempting to unite the party behind Clinton after a combative primary election.

The Sanders campaign did not immediately respond to requests for comment from Insider.

In fact, while Obama has stayed away from endorsing in the 2020 campaign, he has made rare public remarks about his thoughts on the race, including a warning that many interpreted as a critique of Sanders.

"This is still a country that is less revolutionary than it is interested in improvement," Obama said at a November 2019 event in Washington. "They like seeing things improved. But the average American doesn't think that we have to completely tear down the system and remake it. And I think it's important for us not to lose sight of that."