Some time in the early 70's the moron-imbecile-idiot classification disappeared, with moron having the highest IQ of the three, and all three falling under the umbrella of "feeble-mindedness". My vote goes for "imbecile" because he has not progressed beyond the age of six, except that he is a dirty old man.
As a mental health professional, I would not want to diagnose him so that he can't plead insanity or mental retardation and is fully held accountable. He is a lazy, stupid, ignorant, heartless, disgusting, lying bum who refuses to learn anything and to take responsibility for any of his actions, except for the ones that make him look good even if he has to pull them out of his ass. (By the way, have your noticed that his mouth looks like an anus when he speaks?) There is no diagnosis for that, except for the characterizations I have collected to date:
"The toddler in chief
Windbag-in-chief
Fucking moron
Demented man-child in clown makeup
Blowhard
Piece of shit
Idiot-in-chief
Drumpf
Tiny Thumb Diktator
Childish Poltroon
Der Gropinfuror
A bloody git
His Lowness
Goon
President Grabass
A fucking fool
Dumb as shit
Hopeless idiot
Idiot
Dope
President Spithead"
Pick your favorite flavor, it's a matter of personal taste (or lack thereof).
At any rate, he is an interesting, if repugnant, specimen. He belongs in a circus next to the bearded lady. Wait, the White House IS a circus, and he does have Kellyanne! She just has an alternative beard, that's all.
That's all for now, I'm off to barf...