While I may not agree with CB that this (US politics and the current election cycle) is all about white supremacy, I think direct and indirect appeals to racism are a large component of the ongoing GOP primaries (as well as larger politics). The question is, why does it work in the southern states? More than one study has shown that tolerance increases when people are exposed more to the groups they are intolerant towards. By that measure, whites in the southern states, with the largest populations of African-Americans (and perhaps with lesser segregation than in the North?), should have learnt by now to both understand the lives of black people and worked out ways to live with them. However, despite their higher rates of poverty (and therefore, likely, dependence on welfare programs), white people in these very states seem to be the ones who respond enthusiastically to dog whistles (or direct attacks) tying welfare to black people.
Thoughts?
—ravi