You are truly ignorant if you don't understand the dynamics of the democrat party in the South.
I know what I am about to say is politically incorrect in every sense of the word, which is exactly why it needs to be said. Understand this:
After the South lost the War of Northern Aggression, it was a decimated, lawless land, for the most part. Whites, particularly women, were targets of the newly freed slaves and Yankee carpetbaggers who descended on the vanquished population, and rape and murder followed.
Seeing that the US Govt was in no mood to help save our families through committed law-enforcement (after all, abolitionists were in favor of murdering Southern slave-owners and their families anyway), it fell to what was left of Southern manhood to find an effective way to deal with the situation --- hence, the Brotherhood of the Ku Klux Klan was born.
Now let me stop a second and just say that none of this justification of the Klan is EVER mentioned on TV, in the press, popular media, etc. Hell, it pains me to say this, not even the current NRA leadership understands this. However, I know that many a rapist whose neck was stretched deserved just what he got (and still does today), and the fact that the very presence of the Klan on horseback in the moonlight in certain, shall we say, high-crime areas, kept others from straying was a huge benefit for deterrence.
Now, over the many decades since 1865, the South instituted certain laws to keep the races segregated (just as the dictator Lincoln believed they should be), because this is the most effective way to prevent miscegenation, among other degeneracies. These culminated in the very effective Jim Crow laws that are routinely dismissed, but make no mistake, they were effective. These lasted until the democrat LBJ enacted his so-called War on Poverty, and which dramatically changed, FOR THE WORSE, both white and black races in this country.
You see Southerners had identified with the democrat party since Thomas Jefferson started it, and they were naturally anti-Lincoln/Republican, but had started moving away when the Democrat Party of FDR began instituting his socialist policies, then continued to move away from the party of LBJ. You might say, Southerners did not leave the Democrat Party, the party left them.
I realize it's a very difficult mental exercise to understand the subtleties involved in these political machinations, but what is left of the the conservative South found a home in the Republican Party, and they still form the backbone of the party.