It's also worth noting that the initial shifts toward the GOP in some Southern states toward the latter parts of the 20th century weren't even necessarily fueled by native Southerners. For example, Georgia's political geography and statewide margins would have probably looked more like North Carolina's from 2000 to present if you negated the carpetbagger growth between 1975-1995 or so.
IIRC - Bush family has roots in Connecticut. And Bush Sr. was one of the "trailblazers" of Texas Republican party. So - this wasn't limited to Georgia. Nevertheless - local conservative Democrats (Gardner and Helms in North Carolina, Thurmond and Watson - in South Carolina, considerable part of "Byrd's machine" in Virginia, and so on) also played an extremely important role too..
Yes, the states that actually grew at relatively fast clips and had sizable economies (GA, TX, FL - maybe it could be argued VA and possibly even NC to some degree) were all affected to varying degrees by the broader in-migration. It's not as if the trends that began to spill over into rural areas wouldn't have happened regardless, but the statewide effects at minimum would have been delayed and - in states like GA - possibly could have led to the state never leaving swing state status (at least for non-federal elections) if everything else (i.e. Obama coalition etc) played out the same. Pretty much like how NC has been with its Democratic Governors and statewide officers.
Looking at old maps and list of congressmen, to my uneducated eye it looks like the South would've had three parties in a parliamentary system;
1) A suburban movement conservative party (aka the GOP)
2) A centrist (at least economically) rural southern white party
3) An urban/black belt liberal party
Yet the latter two were confined within the Democrats. How did that work within the Democratic Party and the Southern legislatures between the VRA passing and the transition of rural Southern whites to the GOP?
The South still has those three blocks, only now two are in the GOP and one is in the Democratic Party (while the Democrats have made some inroads in Southern suburbs, they are still quite (non-Atlas) red as a whole).
