Florida for EV, New Mexico for PV
Ohio is currently the one that has been right the longest.
Will it be replaced by states like Virginia, New Hampshire, Colorado, Nevada, or Wisconsin if it doesn't go with the winner in 2020? It is currently trending more Republican than many states. What about Iowa?
Until 2008, Missouri had the best track record, but clearly it is hard for the Democrats to regain, at least in a close election.
No, Nevada has, with only Ford and H. Clinton as exceptions and in both cases, those were close.
Ohio grossly voted against JFK and FDRs 4th, and while it did vote for the winner this time, the margin was far to high to count as one.