Donald Trump biographer Tim O’Brien this week warned that the former president’s increasingly “weird” behavior is a warning sign that he doesn’t belong in the White House.

“This is the nominee of the Republican Party and he is deeply unhinged and he is getting worse,” O’Brien told MSNBC’s Joy Reid on Wednesday. “His hearing appears to be getting worse, he’s slurring his speech, and he aspires to lead the most powerful nation on the planet.”

He said it’s easy to make fun of Trump’s bizarre speeches, but added: “It’s also much more profoundly dangerous and troubling, because he’s not fit for office.”

O’Brien tried to interpret Trump’s constant references to fictional “Silence of the Lambs” serial killer Hannibal Lecter.

“Donald Trump actually thinks that migrants seeking asylum belong in insane asylums, and Hannibal Lecter was in an asylum and he can’t really separate the difference from the two,” he said. “So that’s raw ignorance.”

But he said there’s another reason Trump keeps referring to Lecter, an iconic character from two 1980s novels and the films that followed.

“Donald Trump is indeed baked in amber,” he said. “The clothing he wears, the celebrities he fawns over, the music he most closely relates to, is all from the 1980s.”

O’Brien is senior executive editor of Bloomberg Opinion, author of the 2005 book, “TrumpNation: The Art of Being the Donald,” and former executive editor of HuffPost when it was called The Huffington Post.

See his full conversation with Reid below: