For more than a century, the Democrats dominated the South. The Democrats seceded from the Union to protect the slaveholding plutocracy. The Democrats were the ones, under President Wilson, to bring race segregation to Washington, DC. I've heard that many of President FD Roosevelt's programs were explicitly racist, too.
President Nixon, who has always struck me as a bitter man, decided to change the balance of power in the country by a "Southern Strategy," appealing to the racists which had kept his party out of the South for a century. That Nixon himself was a bigot is no secret, but I haven't read that he complained when President Eisenhower used the Nat'l Guard to integrate the schools.
Whether Nixon, or Thurmond by switching after Civil Rights, caused or simply was alert in noticing the re-alignment of the South, it is here. Does the switch, to some degree, also make the Democrats into the pre-64 Republicans? In other words, is the switch just about the issue of race, or is the isolationism of Senator Taft and Eisenhower now naturally a Dem position?
It is, of course, not that simple. FDR's policies may have been affirmative action for poor whites, but they were poor. Even in the 1930s and 40s, the Republicans were the party of the large business interests. The same could be said of the McKinley administration, even though President T Roosevelt ended up being the "trust-buster."
Is this, perhaps, the reason that so many Democrats today feel comfortable with the term "Progressive?"
Just thinking aloud here, thank you for your time.