let them do it. new york is now in play, if enough snowbirds go south, FL could go dem but NY could go for W
If you have two residences you'd be foolish to keep your official on in NY. Florida has not state income tax. People wealthy enough to own houses in both state probably got that way because they were smart about money. Therefore its safe to assume the vast majority are already claiming Florida residence and registered to vote in that state.
If they can do it, so can we. Since we're essentially giving Kerry Mass, and have no real expectation of winning Vermont or even (really) New York, why not have ALL the Republicans in those three states re-register in Florida??
You assume they will only vote in one state. That is a very shaky assumption to make. Remember these are Democrats you are talking about.