I elaborated on it further in my response to Isaac in that subthread between you, him and moondog. Obama absolutely must win FL or OH, and will probably need VA, too, if he only gets OH. He won all three last time, plus NC, on high enthusiastic turnout that will simply not be there this time, and did not have a large margin even then (FL was closest, at 2%; if Rubio is Romneys VP that race is hopeless for Obama.) If Romney runs even as well as McCain did but Obamas turnout dips even a little he loses FL, and possibly OH as well: Game over.