Nixon vs. Reagan landslide

[hcallega]

Also, some of the black belt counties may have been whiter at that time than they are now (Lewis or Al would probably know for sure).

Unlikely. 1972 is at the tail end of the Great Migration, so they would have been getting Whiter at a much lower rate since than before, but that's about it. Southern Urban and suburban (that were suburban even then) counties would have been much whiter than today, of course.

I agree that Muskie, Wallace or Humphrey would have all done better, but Nixon was probably bound to win.