Nobody really takes the time to understand the political situation outside of their immediate surroundings. But the most important part of this is, the geography of partisanship is changing. States change "partisan affiliation" all at once. There are supposedly-blue states that will be red soon, and, in the medium term, several southern Atlantic states are going to go blue.

I think things are too fluid to predict any kind of clear geographic fault line.

What would be interesting would be if a state somehow broke up.