Counties Obama can flip from red to blue

[Donerail]

Probably not many out there but I think there will be a few. Here are my possibilities:
NC: Nash, Franklin
VA: Southampton
FL: Sarasota, Seminole(stretch here)
PA: not really buying idea of SW flipping back so none
CA: Orange (possible but unlikely barring national shift)
TX: Fort Bend
NJ: Monmouth- this too is a stretch

Sarasota and maybe Pasco seem the most likely in Florida. Seminole'll stay R for another couple cycles, but demographics will make it D in 10-20 years. Obama did pretty well in Hernando County too, so there's that.

[Donerail]

Just some wild guesses
Duval, Seminole, Pasco, Hernando - Florida.
Maricopa - Arizona.
Frederick, Anne Arundel - Maryland.

I don't see any way Obama can pick up Duval. It may he the largest city in Florida, but it's Republican, very much so. The mayoral election was a fluke. Seminole's a massive Republican stronghold; maybe in 2020 or something demographics will make it competitive, but not now. Pasco/Hernando, however, are competitive, and Obama has a real shot, especially in Pasco.