For Donald Trump, there is no harsher attack that could be leveled.

In an interview with Variety magazine, Fox News host Megyn Kelly, who Trump has obsessively attacked for not giving him fawning coverage, offhandedly questioned whether the Republican front-runner was really a billionaire.

“I think she’d be a fascinating interview,” Kelly said, explaining why she would like to interview Trump’s wife Melania. “She’s beautiful. She’s an entrepreneur. She could have married this billionaire — I don’t know if he’s a billionaire — and taken it easy, but she was determined to create her own business. I’ve been impressed by her grace, her kindness. I think she speaks well for him. All this controversial stuff that he has said and done, how does she view it? I bet she doesn’t like it. I bet she tells him to stop.”

Trump is famously insecure about people questioning how much his net worth really is. Comedian Anthony Jeselnik revealed that the only topic Trump told Comedy Central was off limits for comedians during his 2011 televised roast were jokes about whether he was really worth as much as he claims.

[dcquiz] In 2005, Trump actually sued an author for $5 billion for reporting in a book that Trump may only be worth hundreds of millions of dollars, not billions.

During his presidential campaign, Trump has made his business success and wealth a major focus of his candidacy, claiming his net worth to be well over $10 billion. Forbes Magazine pegs it closer to $4.5 billion, while a Bloomberg analysis said Trump was worth around $2.9 billion.

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