As I keep saying - and as Tony Schwartz said a few pages. I don't know why people keep being surprised, or thinking this is Trump feeling confident. It's the opposite. Trump has been psychically shaking with fear of humiliation and being called a loser most of his life. It is a deep part of his psyche. He will stop at absolutely nothing to attack when he is told no or forced to comply with something opposite to his own wishes. Every time he has been made to walk something back or change his tone, he always doubles or triples down days later like a child. This is just the latest and worst example.
I still think it will be resignation to evade prosecution or exposure, but 25th Amendment odds just got a little better.