So you're saying that someone can be elected president without being on the ballot on all 50 States?
Seems doubtful.
What's to prevent the top electoral vote States from getting together and creating unified laws that enable them to elect the president they want, and simply cut out every other State?
No, I think that a candidate for president OF all 50 States must be qualified IN all 50 States, as long as the qualification requirements are limited to simply verifying the Constitutional requirements.
And btw, this won't just stop with the States - there are also Constitutional requirements for verification that were dismissed by Pelosi and Boehner last time, that their positions can be held to this time.
Technically, the candidates aren't on the ballot - electors pledged to vote for them in the Electoral College are. I have no idea, and I doubt there are any precedents, whether a state's Attorney General (say) can invalidate a vote in the EC on the grounds that the Elector can't vote for someone unqualified under that state's laws. The House can (I think) when it formally counts the Electoral Vote.
What's to prevent the top electoral vote States from getting together and creating unified laws that enable them to elect the president they want, and simply cut out every other State?
It's called "National Popular Vote"