I've also heard of the many racist Southern Democrats who opposed civil rights and remained Democrats after 1964 (many much longer), including: John Stennis, Herman Talmadge, James Eastland, Allen Ellender, Russell Long, John Sparkman, John McClellan, Richard Russell, George Wallace, Lester Maddox, John Rarick, Robert Byrd, and Al Gore, Sr.
But are you really going to defend the Party of Trump as being inclusive?
Are you really claiming that the Southern Strategy didn’t exist despite the words of Lee Atwater?
And the claim that interview with Lee Atwater is talking about Republican strategy makes no sense. It starts with "in 1954 you start out saying n....r, n....r, n....r." But in 1954 the South was solidly Democratic and Republicans were sending troops there to force integration. The quote describes a supposed "southern strategy" beginning in 1954 that bears no relation to reality in 1954. Why should we believe the rest of it when it's wrong from the beginning?
But, parties change and they try to appeal to enough different coalitions to get elected. The Republican Party use to be about free trade, "pulling yourself up by the bootstraps and not blaming others for your plight in life" and at least give lip service to caring about the deficit. Now they are completely the opposite.
I certainly agree that parties' political positions change. That doesn't mean any particular claim of change is true.
https://www.youtube.com/watch?v=X_8E3ENrKrQ
And you have heard of Strom Thurman haven’t you?