Look, I understand there is a racist mood in the South in some people. I've lived in the South for over 25 years. But racism isn't the reason there are different political parties.
Southern voters are angry at Democrats for a number of reasons. A big reason is religion. The south is more religiously conservative. They see the Democrats as a threat to the family unit and religious traditions such as marriage. This also leads into other issues such as gay marriage, abortion, women's rights, etc. Another reason the South hates Democrats is guns. Conservatives genuinely fear the Democrats are trying to confiscate their guns.
There is also simply a different economic philosophy in the South and the country as a whole. Conservatives would prefer a more laissez-faire capitalist system. Liberals would prefer a more hybrid socialist system.
One more thing, are you also suggesting that racism is excursively a Republican/conservative phenomenon? I can say that I have personally run into far-left liberal Democrats who are just as racist as any Conservative.
Republicans may try to use racist feelings to solidify some voting blocs. But racism isn't the reason we have political divide in America. We have 320 million people in this country. Getting all to agree on ANYTHING is impossible. You will ALWAYS have political division and dissension. That's the reality of a democracy.