I was thinking about how the states in the southern US are reliably red at large despite their large black populations which votes for Democrats. I read about it and found that over 70% of white voters in Southern states vote for Republicans. By contrast, 90 to 96 percent of black voters vote for Democrats in the South. By the south, I will mean the sun belt states from South Carolina to Texas excluding Florida (kind of).
Is there any policy by either party that drove white southerners away from Democrats? And why is this?