All true, but again, look up the Southern Strategy.
https://en.m.wikipedia.org/wiki/Southern_strategy
Today's Democrats would not be comfortable in the Democratic Party of the sixties.
Today's Republicans would not be comfortable in the Republican Party of the sixties.
Senator Byrd, in particular, is an interesting case study in the swing that happened in the parties between the 60s and today. The story of how he went from the guy who filibustered the Civil Rights Act to a guy who scored 100% agreement with the NAACP on legislative initiatives is a fascinating microcosm of American politics during that time period.