Amazing to me how many counties in the South (for example, Walker and Cherokee counties in Alabama) backed Michael Dukakis, a self-proclaimed liberal. The swing to the Republicans over the last 20 years in these areas has been remarkable and massive.
This is not quite true.
Virginia is lean D consistently now. Florida is a tossup, and North Carolina is tilt R. Georgia and Texas are on the path to becoming swing states. South Carolina and Mississippi are more Democratic at the Presidential level than they were in 1988, and significantly so. These are the areas of the South that are gaining in minorities as a percentage of the population, and where the white population has a significant number of Northern transplants. (Mississippi is an exception to the latter, but blacks as a percentage of the population, and of the voting population, is increasing.)
The parts of the South that have swung the most toward the GOP are, arguably, the states that were Bill Clinton's best states. Arkansas, Tennessee, and Louisiana have swung sharply to the GOP. Arkansas and Tennessee have swung because they have low black populations, and because they are highly religious, churchgoing states, while the Democrats have become progressively more hostile to Evangelicals. Louisiana's shift has resulted due to the Cajun Catholics swinging to the GOP on all levels, in no small measure due to the abortion issue, as well as the Democratic Party's hostility to the Fossil Fuel industry. The trend toward the GOP has not been uniform amongst white Southern voters; the Anglo-Saxon white voters and the Scot-Irish white voters have led the way for the most part.
What HAS happened in the South is that the South, as a whole, is more Republican at the local and state level. This has been partly due to the fact that Southern white conservative Democratic voters found themselves voting for Democrats who said they were conservatives, but who provided key support for liberal legislation as needed. The end of the seniority system in Congress and the process of making committee chairs more responsive to the Democratic caucus enhanced the disconnect between the average Southern Democrat and his/her LOCAL candidates. The end result of all of this is that nowadays, state Democratic Parties in the South are pretty much as liberal as they wish to be; they're hope is in changing demographics, and not in winning the hearts and minds of moderate white voters.