That band of blue counties in Alabama includes some of the poorest counties in the nation. These are areas that never rebounded from the great depression. What amazes me is that they consistently vote democrat...they’ve been in poverty for almost 100 years, and they still vote the same way, because of identity politics.
I live in that band of minority voters in Alabama. I never have figured it out. Most of the them are good people. This is the area that had the really large cotton plantations before the War. I guess most blacks just stayed on the plantation, so to speak.
That's called the 'Black Belt'...not because of race but soil color, albeit, they're majority Black by race, some counties, close to 90% Black.. That's some of the best farming soil in the world and is where the majority of Black slaves lived and worked in times past, cotton farming. Same with the grouping of Blacks along the Mississipi river.
Now, FYI.
I've read that the areas in the Appalachian mountains, settled mostly my the Irish and Scots are the largest groupings of unintegrated White people in the world.