"Whack Job"

John Podesta of the DNC just referred to POTUS45 as a "whack job."

First I thought, this is news? My next thought, hmm, thought I was the only person in the world who still uses that phrase, "whack job." To me it refers to the lack of ability to manage one's own emotions, and in particular if the disregulation reaches the point where the person can't control what he says.

Do we have any other words or phrases in general use that capture that meaning?