While we're on the subject, I think this is the most basic breakdown for me (I think that just because DC was such a crutial "breaking point" in the Civil War, I am fine with letting Maryland and Delaware shed their original Southern stock for Northeastern):
However, if we are going to divide by subregion, my map would look something like this:
THE NORTHEASTDark Red: New England
Red: Non-New England Northeast
Pink: More Mid-Atlantic
THE SOUTHDark Green: The Deep South
Green: Clearly Southern but significant differences from the Deep South
Light Green: Part of the geographic region that is the South, some culturally Southern areas, but a very significant population of people who would not identify as Southern
THE MIDWESTDark Blue: The core of the Midwest, Big Ten Country, etc.
Blue: The Plains, clearly Midwestern but different culturally than Big Ten Country (more of a Western influence)
Light Blue: Really just fits into the Midwest by default ... parts of it are Plains-ish (KC), parts are Midwestern (STL), parts are Southern
THE WESTDark Yellow: West Coast
Yellow: Southwest
Light Yellow: Mountain West
Gray: When you do subregions, Alaska and Hawaii really just deserve their own, LOL.