I’m interested to know of areas not impacted entirely by white transplants.
I’ll add that the places that are voting blue, such as Columbia/Charleston SC, are growing in part of the death of rural areas. I know just as many people who ended up living in Greenville/Columbia/Charleston as I do who stayed in the area after high school.
I’d say those that move out are generally more the type of voters that are becoming democratic (young, college educated, median income). This isn’t the only reason these cities are trending blue, but definitely a part of it.
The type of people who are becoming democrats are the kind want amenities (parks, bars, schools with running water) that just aren’t as accessible or existent then where they’re from. So they move to these larger cities to get them, and also happen to shift local politics some.