“... Democrats would become competitive in the Deep South again...”
This seems a bit over optimistic. Win a few yes. Competitive? Hardly. NC,VA,maybe TX but where else? If this means the rat wins SOMETHING in every Southern State, well yes. But “competitive” should be more than 25%.
John Kerry got more than 40% of the vote in every state of the Old Confederacy, save two - where he got 38% and 37%.
In six deep South states, he got more than 42%, and in three, he got more than 45%.
I would say that the RATs are "competitive" by your definition all over the deep South.