>>512384914 (OP)The Democrats were pro-slavery and then pro-segregation. After segregation became a bipartisan "no", pro-states-rights Republicans started getting the Southerners' votes because they supported segregation from a Constitutional perspective. The Dixiecrats that supported Jim Crow laws began to vote Republican ever since then. This event is sometimes called "The Party Swap", or "The Southern Strategy".
This surface-level propaganda is easily seen through and it wouldn't matter if it was true, anyway. The fact-of-the-matter is that racist people from the south vote Republican because they represent their racist interests.