Nate Silver floats the idea of Andrew Cuomo as Obama's successor:
Whoever is the Democratic nominee in 2016, he or she will almost certainly endorse same-sex marriage, as about two-thirds of Democratic voters already do. But it’s unlikely that any of them will be able to better Mr. Cuomo’s accomplishment. Particularly if Mr. Obama loses next year, his approach toward leadership is one that many Democratic voters will have an appetite for.
Cuomo is keeping his cards close for now.