Don’t discount the Mississippi comment - they worked many years to turn Georgia and Virginia - they no doubt will work on other deep red states to flip. We have to work on these states just as hard...even those supposedly “in the bag” for us as it can slip away if we are not looking.
Carville is right. Once black population hits 25% it gets a lot easier to elect Dems. You only need about 1 of 4 whites to vote Dem and the races get real close.
Mississippi and S. Carolina could be prime targets for Dems. That is one reason having a black Republican Senator like Tim Scott in S.Carolina is important.