Donald Trump, Cher Donald Trump, Cher

Donald Trump has opened his mouth again — and this time he's going after Cher.

Donald Trump: Rosie O'Donnell is a failure

The real estate mogul slammed the singer on Fox News Monday, calling her lonely and miserable, when he called in to Greta Van Susteren's show to talk about the President Barack Obama's campaign ad that calls Mitt Romney a "job destroyer" for his involvement with Bain Capital. (You can watch the ad here.) The conversation later turned to Trump's tweet war with Cher over her comments on Romney.

Last week Cher tweeted, "If ROMNEY gets elected I don't know if I can breathe same air as Him & his Right Wing Racist Homophobic Women Hating Tea Bagger Masters." Trump later responded, "@Cher should stop with the bad plastic surgery and nasty statements about good people running for office. I can't stand her computer enhanced voice or music."

Trump told Van Susteren on Monday: "She's lonely, she's unhappy, she's very miserable, and her sound-enhanced and computer-enhanced music doesn't do it for me, believe me."

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During his tweet war with Cher, Trump had also brought his nemesis Rosie O'Donnell into the conversation, saying, "[Cher] is an average talent who is out of touch with reality. Like Rosie O'Donnell, a total loser!"

When Van Susteren asked Trump about bringing O'Donnell into the fight, he said, "Well, I likened her to Rosie as a loser. But, you know, I understand Cher, and Cher is somewhat of a loser... I've watched her over the years, she reminds me of Rosie with slightly more talent, not much more talent, but slightly more talent."

Watch the interview here: