First of all, you did not specify “The South” in your post and the Democrats as a party nominated a hard Left anti-war (and all the socialist rhetoric that came with that movement) in George McGovern in 1972.
The McGovern folks took over the platform and moved the party hard Left that year. The party never recovered.
In the mid 60s you had McGovern, and a bunch of other progressively Leftist Democrats buying into the anti-War movement. By 1972, they wrestled control of the party away from the more moderates and we’ve had strident Leftist candidates from the Leftist (Democrats) ever since.
This is not a commentary on the Democrats of the South. It’s just a hard cold fact about the overall party.
the Democrat party of today is much further to the left than it was 40 years ago.. it’s just a no brainer fact and I think some unions like the pro American Teamsters have almost nothing in common with the America hating, tax raising, job losing, muzzie loving leftists who are the Democrat party of today.. there is NO WAY an avowed self described socialist could have run for President on the Democratic ticket 40 years ago let alone be leading in some of their polls for President.. no way.