what!? like Gaias Caligula? or Nero? "What an artist" in his famous last words. yes maybe. at least Caligula only waged a war on Neptune and gathered up as many of Neptunes wealth (sea shells) as they could carry.... and Nero warred with no-one as he was too busy performing transvestite dance and song.....
Trump already seemed to believe he had impunity in his last term. what he does next is likely to be more of the same, so yeh... no telling what he might do.
but a coup? not likely imo. unless Trump loses and so far I can't see that he can possibly lose (against Biden)