The Greeks had a word for it: Hubris.
As in Greek tragedies, where the main character was found to have overreached his abilities and rejected any humility.
Some modern phrases such as, “Too big for his pants,” or “The bigger they are, the harder they fall,” are applicable. Or from Proverbs 16:18, paraphrased in McGuffey Readers, “Pride goeth before the fall.”
My Dad would call a haughty blowhard, “A big-feelin’ cuss.”
The Greek choruses and audience would see how this pride-ful character, usually a leader or king of some sort, was headed for a fall, though the character himself couldn’t see it coming. He was too powerful and into himself to see his flaws. He would not take blame for his actions, and furthermore blamed others. His past successes in bamboozling others was proof that he could continue his con game without failure.
But eventually, the Greek gods would put him down, usually using his own hidden ignorance and incompetence to make him do it to himself.
From being oblivious to oblivion, in one final act.
Delighting the Greek audiences in seeing the big bully have his just desserts.
So there may be a slim hope today that a bizarre, clueless leader can bring himself down without any help from the Greek citizens or AWOL gods. Maybe. If only we were living in a Greek amphitheater.
Now if you interpret this analysis as applying to anyone in the public realm today, it is purely coincidental. Didn’t mean it. Really.