As the Democrats -- once the agrarian, free trade party, then the party of the poorer South and West -- became more urban and liberal, the outlying areas of the South started to drift to the Republicans: Virginia, Tennessee, Texas, Florida.
The Deep South was Democrat until the Second Reconstruction -- the civil rights movement and civil rights acts of the 1960s -- or even later if we're talking about Congressional delegations.
As the older Senators and Congressmen died off and their seniority was lost, Southern states moved more firmly into the Republican column for ideological reasons, the Republicans having become the party of less government.
Correct