"I think, in his mind, the success of this is going to be the poll numbers."
And that, in a nutshell, is what is bringing him down.  As more and more of the nation comes out against him, he's going to crack.  He clearly didn't realize that he's going to be under this intense microscope for the next four years (if he makes it) in this job, and every move he makes is going to receive lots of criticism.  Look how every past president has aged on the job.  But he brought it on himself, drawing as much attention as possible with his idiotic tweets and such.