The logic of the current Democratic primary contest dictates that Michael Bloomberg portray himself as Barack Obama’s true heir. And so, with Bloomberg’s vast resources, it has come to pass. A 30-second spot began circulating earlier this month that portrays Bloomberg and Obama as close allies. The spot pairs photos of the two together with encomiums from the former president. “I want to thank the mayor of this great city, Mayor Bloomberg, for his extraordinary leadership,” Obama intones at one point.

Obamaworld, with its long memory, was not happy. “I was triggered by the ad,” a former Obama official said. “The ubiquity of the ads is what bothers me,” Dan Pfeiffer, Obama’s former communications director told me. “Bloomberg didn’t endorse Obama in 2008, and in 2012 he offered a tepid endorsement that included parts that read like an RNC attack ad.”

Several recent reports have acknowledged Bloomberg’s policy differences with Obama, but sources close to both men tell me the antagonism runs much deeper. In private, Obama thinks Bloomberg acted high-handed and arrogant, while Bloomberg has told friends that Obama is a lightweight, sources said. “Mike would have dinner parties and piss all over Obama when he was president. I know because I attended them,” a prominent Democratic donor told me.

The chasm between Bloomberg and Obama first opened when Obama ran in 2007. Bloomberg seriously toyed with the idea of running for president, a longtime dream of his chief political adviser Kevin Sheekey. When Bloomberg didn’t get into the race, he backed fellow Republican John McCain. At a dinner party during the 2008 election, a source remembers Bloomberg’s longtime girlfriend, Diana Taylor, getting into an argument with Sheekey’s wife, who was supporting Obama. “How can you be so stupid to be for someone like Obama?” Taylor asked, the person told me. “Diana was repeating what Mike would say about Obama, except it was louder,” the source recalled. (The Bloomberg campaign did not respond to a request for comment.)

A confidant of both Bloomberg and Obama told me the tension between them was in part fueled by Bloomberg’s belief that he should be president. “Bloomberg would belittle Obama in private. It was like, That should have been me in the White House. There was jealousy there,” the source said.

Although Bloomberg is running to defeat Donald Trump, some people close to the campaign say Bloomberg’s embrace of Obama is, well, Trumpian. “It’s becoming an incredible turnoff. He’s flooding the airwaves with nonstop ads that are just not accurate,” a prominent Democrat who speaks frequently to the campaign told me. Another person with close ties to the campaign said Bloomberg’s strategy is, in effect, to say whatever he needs to say to win key states on Super Tuesday. According to the source, Bloomberg didn’t want to debate the other candidates. The campaign had hoped to saturate television with ads and avoid the press until Super Tuesday, but the DNC changed the requirements to put him onstage. “There are no rules on the campaign,” the source said.

More Great Stories From Vanity Fair

—After acquittal, Trump plots revenge on Bolton and other impeachment enemies

— Behind the scenes of Trump’s secret birther implosion

— Why Bernie’s message and media machine could be potent against Trump

— With accused wife-murderer Fotis Dulos on life support, a look inside the grim end of a perfect couple

— The hedge fund vampire that bleeds newspapers dry now has the Chicago Tribune by the throat

— The most deranged moments from Trump’s post-acquittal press conference

— From the Archive: If Donald Trump is the political equivalent of a pathogen, who’s responsible for letting him wreak havoc in the national bloodstream?

Looking for more? Sign up for our daily Hive newsletter and never miss a story.