i don't have a real rational explanation, if i did, we could probably come up for a cure for stupidity, or at least republicanism...
and there are certainly a lot of red dots on the map in other parts of the country, but the south east is a solid bar of red with a few purple polka dots...
the south east is also not an educational oasis...
https://personal.tcu.edu/kylewalker/maps/education/#4.76/28.94/-88.88
i don't see very many green or blue spots in florida at all, and 90%+ in texas are clustered around the bigger cities.
there are educated people in the south, but they're a lot fewer and further between than in the north, the north east in particular.
and the level of poorly educated coincides almost perfectly with the distribution of republicans...