Yes,
The Hispanic share of the population is increasing rapidly in Texas and I think the black shares of MS & SC are increasing as well (albeit at a smaller rate). It will be a while before this change is enough to affect MS & SC, but Texas should be in play within a generation or so.
In the Deep south and Texas, yes, but in the upper south/appalachia, at a federal level, the party is currently dying a death. Only Hillary Clinton could flip those states sort term, long term it will take a huge change of direction OR regional tokenism.
Ironically, until the deep south is 48%+ Dem, the population growth there will benefit the GOP in the short term by giving them more electoral votes relative to liberal northern states. Even if there margins there are being eroded, a state 51% GOP with 12 ECV's is worth more than a 59% GOP state worth 9.
Virginia, N+S Carolina, Georgia, Louisiana, Texas and Missisippi can easily flip Dem within 16 years or so. Others I can only see in a Blowout.
