The former head of the Democratic National Committee slammed President Trump in an interview Sunday, deeming him "mentally incapacitated."

Howard Dean, also the former governor of Vermont, said during the interview on MSNBC that he's had that belief for "quite some time."

"He says things that he knows aren't true," Dean said, while discussing the president's tweet blaming deaths at the border on the Democrats' "pathetic immigration policies."

He went on to say that Trump's staff is "terrified" and that the president is a "completely irrational person."

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Former Secret Service agent Dan Bongino said Monday on "Fox & Friends" that he'd take a "seriously hard pass" on Dean's opinion.

"I'll take Trump any day of the week, and twice on Sunday," Bongino said.

Dean had previously called Trump "mentally ill" in September, following the death of Sen. John McCain.

"Trump has been an outlier since he’s been president and he’s not a particularly well-respected person," Dean said at the time.

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