No community is immune from racism, but the south is known for it. So much that people actually have to say 'non racist southerners" when describing non racist people there. You don't have to say "non racist northerners". "non racist Californians". "Non racist New Yorkers". There are racist people in these places, obviously, but they don't have the reputation to shake. So many decades of racially divisive politics in the south (right up to the most recent election) doesn't help. It's going to be a long time before the south shakes this reputation.