I think many, not all, do have that impression of the South or at least some parts of the South. To some I'm sure we are just a butt of a joke.
As for RP's post above you are right and I wouldn't dispute that at all. As a Christian though, myself, I cringe when I see Christian attached or Jesus Christ attached to anything like that or Racism. Fact is that is not Christian or true Christianity. Christianity teaches and lives Love to all races and peoples for TRUE Christianity (and the way it does it is) looks at people/humans as God's Creation of a person with an inner spirit/soul that lives on. When a true Christian looks at another individual they don't see skin color, nationality, accent but rather they see them as I believe God sees them and that is as a soul/spirit that has no other identity. It is someone just as we are just like us in every way therefore no basis for discrimination. I realize that's not the case with the people you cited but just like the KKK they can carry the cross or name of Christ but that does not make them partakers with Christ or Christians. Hate, Racism, Bias are works and actions of the flesh, being human and everyone is subject to those feelings just like everyone else.
Usually though those things are caused by a limitation of education or restricting our minds to a very confined belief or system of which they feel they are an integral part of. They are usually followers and incapable of making their own decisions.