Rep. Jasmine Crockett says President Trump‘s latest attack on her is a warning sign … she says he either has dementia, or he’s just dumb as a rock.

The Democratic Congresswoman from Texas joined us on “TMZ Live” Monday and we asked about Trump calling her a very low IQ individual and challenging her to take a cognitive exam.

Crockett says the only one lacking any brain cells here is Trump … and she rattles off a list of differences between their life achievements — going jab-for-jab with POTUS, and mixing in some shots at his social media platform.

Crockett unloads on Trump and wonders if it’s “Dementia Don” or “Dumb Don” behind the keyboard here … and she also tells us whether she’s willing to take him up on his exam offer.