Actually, the election evidence shows that the GOP absorbed the Peripheral South and gained in the South primarily from the importing transplants into the region, not by converting Dixiecrats and Democratic Party KKK leaders like Robert Byrd into Republicans. The racist Democrats in the Solid South primarily stayed Democrats. The GOP got more votes from the non-racists, both among the existing population and from immigrants from other States to turn the South into their voting block, beginning with the least (not most) racist States. The details have been written up in many places, but here’s one I found with a quick Google search if you’re looking for more details.
To quote that article in relation to the myth you keep trying to spread:
"Starting in the 1950s, the South attracted millions of Midwesterners, Northeasterners, and other transplants. These "immigrants" identified themselves as Republicans at higher rates than native whites. In the 1980s, up to a quarter of self-declared Republicans in Texas appear to have been such immigrants. Furthermore, research consistently shows that identification with the GOP is stronger among the South's younger rather than older white voters, and that each cohort has also became more Republican with time. Do we really believe immigrants were more racist than native Southerners, and that younger Southerners identified more with white solidarity than did their elders, and that all cohorts did so more by the 1980s and '90s than they had earlier?
In sum, the GOP's Southern electorate was not rural, nativist, less educated, afraid of change, or concentrated in the most stagnant parts of the Deep South. It was disproportionately suburban, middle-class, educated, younger, non-native-Southern, and concentrated in the growth-points that were, so to speak, the least "Southern" parts of the South."
Or as the NY Times put it:
"In the postwar era, they note, the South transformed itself from a backward region to an engine of the national economy, giving rise to a sizable new wealthy suburban class. This class, not surprisingly, began to vote for the party that best represented its economic interests: the G.O.P. Working-class whites, however — and here’s the surprise — even those in areas with large black populations, stayed loyal to the Democrats. (This was true until the 90s, when the nation as a whole turned rightward in Congressional voting.)
The two scholars support their claim with an extensive survey of election returns and voter surveys. To give just one example: in the 50s, among Southerners in the low-income tercile, 43 percent voted for Republican Presidential candidates, while in the high-income tercile, 53 percent voted Republican; by the 80s, those figures were 51 percent and 77 percent, respectively. Wealthy Southerners shifted rightward in droves but poorer ones didn’t."