Shelby County is majority black. Obama will break 60% easily here.
I'm just saying it's within the theoretical realm of possibility, not that it's likely (it would have to be like Nixon '72). Bush "only" lost there by 16 points.
There's no way Romney is winning Shelby County unless he wins in a 1984-type landslide. It's also pretty unlikely he'll win Davidson.
Even if he does win a 1984-type landslide he won't win Shelby because its 48.5% black or Haywood county which is 51% black. It would take a live boy dead girl situation for Obama or a completely unforseen realignment for that to happen.