For all people talk 'bout Western PA's move away, them Philly 'Burbs practically make the difference...which itself wouldn't have been that thinkable even four years ago.
Keep Chester flipped and improve/retain Bucks, and along with the rest of Philly and Pittsburgh, that's a good counter.
Whereas Florida's a hodgepodge.
In such a case, it would seem an insane Broward margin and flipping Jacksonville would have to occur for FL to move left significantly.
That and Pinellas Seminole, and St. Lucie would probably flip and maybe Monroe would swing back, too. I think that happens to the next D that wins statewide.
The next Dem that wins Florida will win Duval County, plus the Obama 2012 Florida map. I'd even wager on a couple northern counties as a possibility.