On Economics- GOP has always been more right wing
Foreign Policy- They were about the same until the 1970s when the GOP became more hawkish
Social Policy- Gradual from truman to lbj
Basically this.
A lot of people fighting strawmen in this thread. No one with any knowledge of the situation thinks that one day in 1964 Johnson sent Strom Thurmond over to the Republican caucus with a briefcase full of political positions and asked them to send theirs over. And I think one would have to be willfully ignorant to deny that the cultural conservatism which was once the basis of the Solid South is now almost completely in the Republican camp. The question is not whether these trends exist, because they clearly do, but to what extent they exist, what issues they touch, and how long it took for them to become apparent.