The guy hasn't been in office for a day yet, and we're already talking about him winning by a Reaganesque margin.
What if he doesn't have a first term that solves the world's problems like he's promised?
Then he won't do that well, obviously. But historically, presidents win pretty solid re-election victories, unless they're unpopular.
Historically, presidents don't take office with the problems we have right now.
Well... the last president to take office with problems of similar magnitude, though at a later point in the circle, was one Franklin D Roosevelt...