Rather than ask me to explain why three people switched parties, you should explain why so many Southern segregationists (all but 3) didn't switch parties if the Democrats were suddenly the party of civil rights.

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?

He was talking about how you had to change your approach to appeal to racists over the years. In 1954, you could appeal to racists more overtly in the south to win them over. But over the years you had to be more careful.

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 don't like debating out of context quotes, but I suspect he was describing Strom Thurmond's campaign strategy. He worked for Strom Thurmond and that would fit in 1954 as well. But one politician's strategy is a far cry from a general Republican southern strategy.

I certainly agree that parties' political positions change. That doesn't mean any particular claim of change is true.