Yes, any state could do this. No state will decide who goes on their ballots until after the primaries though. They can “declare” things all they want, but nothing is actionable until the ballots are finalized (and then the suing starts).
Yes, and if he becomes the nominee, that will have to be done. But in the end it won’t matter unless enough states successfully do it to deprive him of 270 electoral college votes.
Can’t you just challenge him being put on the ballet in your state?
Yes, any state could do this. No state will decide who goes on their ballots until after the primaries though. They can “declare” things all they want, but nothing is actionable until the ballots are finalized (and then the suing starts).
Yes, and if he becomes the nominee, that will have to be done. But in the end it won’t matter unless enough states successfully do it to deprive him of 270 electoral college votes.