In reading an article about Trump's run-in with Jeff Flake, while ostensibly on a mission to "unite" the GOP behind him, it occurred to me that The Donald will only degrade as a viable candidate from here on out. While he had very little in the way of a substantial platform during the primaries, he will now have progressively less.
His greatness has been affirmed by the nomination and the foremost task for his narcissistic self is now to protect his greatness against his enemies, many of whom are Republicans. Since he has no advisors except himself, and no campaign strategy or team, I expect his behavior to shift almost entirely to attacking his detractors. (Maybe that's not really a shift?)
In any case, the necessary pivot for him, as a contender, to real issues and to appearing Presidential, is not going to happen.
