Former Democratic presidential candidate Gary Hart said in an interview set to broadcast Sunday that President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE has shown that "anyone can be president."

In an interview that will air on "CBS Sunday Morning," Hart also said that he thinks "all the rules have changed."

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“If Donald Trump can have a fan base of 30-40 percent despite everything he’s done in life, all bets are off. Anybody can be president, regardless," he said.

Hart, who was also a senator from Colorado from 1975 to 1987, ran to be the Democratic presidential nominee in 1988. But his campaign was derailed when the Miami Herald published a story describing allegations that he had an affair with the actress Donna Rice.

Hart told "CBS Sunday Morning" that it was "nobody's business" whether he had an affair and that a reporter who asked whether he had been unfaithful shouldn't have done so.

"Character, which got to be the key word, is demonstrated over a lifetime. And I’ll put my life up against anybody else’s in terms of sound character. That’s all I can say," he said.

A movie about Hart's rise and fall, "The Front Runner," was released on Nov. 6.