I don't know. I'm reminded of a Simpsons' episode back in the 90s when they were doing George Bush. He was reading from his autobiography and finished up by saying "... and therefore, having accomplished everything I wanted to do in a single term, I didn't see the need to try and get elected for a second one".
Trump has the ability to be as completely revisionist as he wants. I can totally see him saying something along the lines of "Washington is SO broken that even as President, I couldn't effect the kinds of changes which are needed from inside the system as I'll be able to do from outside it. Therefore, even though I have been, without question, the most popular, successful and effective President in history, I am resigning the post so that the American people can be lucky enough to benefit from my leadership where I'll be able to do the best work".
If it gets his finger off of the nuclear trigger one minute sooner, I'd be good with everyone agreeing with him and giving him a victory parade out of town.
