Billionaire Barry Diller thinks Elon Musk has a 'form of megalomania' and is backing Trump after being rejected by Biden

• Barry Diller suggested Elon Musk endorsed Donald Trump due to "rejection" by the Biden administration.
• He also told Michael Wolff's podcast that Musk was motivated by "a form of megalomania."
• The IAC and Expedia chairman criticized Musk for alienating X users.

Barry Diller thinks Elon Musk is backing Donald Trump because he's bitter about being rejected by the Democrats, the billionaire told the "Fire and Fury" podcast .

Musk officially endorsed Trump after the former President was shot at a rally in Pennsylvania in July. He also created a super PAC, the America PAC , that has spent more than $80 million on the election.

"Why he has gone this way, I think, is out of some weird bitterness and rejection by the current administration," Diller told presenters Michael Wolff and James Truman.

Musk was once a supporter of Joe Biden, but the pair have often sparred verbally since Biden took office in 2021.

In July the Tesla and SpaceX CEO said he once considered the Democrats to favor meritocracy, "personal freedom" and "free speech ," but now thought Republicans were "weirdly" more in line with those values.

Diller also said he thought Musk, the world's richest person, was not motivated by wealth but "a form of megalomania."

Diller, who cofounded the Fox TV network with Rupert Murdoch and once ran Paramount, is a major donor to the Democratic Party .

On the podcast, the IAC and Expedia chairman also spoke of his admiration for Musk, highlighting his intelligence and managerial ability.

However, Diller added that Musk had a "capacious but often addled mind" — with his politicized statements hurting revenue at X, formerly Twitter.

"He took over Twitter and alienated at least half the audience for no reason other than his own talking," Diller said. "What hurt Twitter was his anti-advertising policies and statements that hurt Twitter's economy."

The likes of Disney and Apple withdrew ads from the platform after Musk agreed with an antisemitic post last November. At The New York Times' DealBook Summit the same month, Musk told departing advertisers to "go fuck yourself."

This August, X filed lawsuits against several major advertisers, claiming that a boycott violated antitrust laws.

Musk paid $44 billion to take control of Twitter in October 2022. It's now worth less than $10 billion according to the value Fidelity assigned to its stake in the company, CNN reported last month.

Shortly after the takeover, Diller said Musk had " bought a toy ," adding: "How long he will use it, like toys, we don't really know, but he's not going to walk away, I don't think."

Diller is worth about $4.6 billion, per Forbes.

X did not immediately respond to a request for comment from Business Insider.