The failure of the Southern Strategy to emerge is probably somewhat due to the fact that you've had GOP presidential candidates who weren't interested in exploiting racial tensions. George Romney was just as much a supporter of civil rights as Hubert Humphrey. It seems like, without the far right agitators pushing racial divisiveness as in the OTL, southern Democrats have settled down and learned to live with the end of Jim Crow.
Indeed. With Nixon failing to get nominated for President and Reagan being largely kept at bay by the moderate-liberal wing of the GOP, the Southern Strategy is largely discredited.
Then again, a big part of this timeline is presenting a more idealistic (but still realistic) world.