Republican "party"? Maybe not. But the voters, who were registered Democrats, began switching their votes to Republican during this movement in the 1960's. Ever wonder why the Deep South is all Red today? Hmmm.....but it was once all Blue before 1960's? Hmm......Any connection? Ya think?
It's all red today because the elite libs took the party ever leftward. They supported much higher taxes, much larger government with more power, they opposed the war, they supported the riots of the 60's, they became the party of drugs and free sex. Many, many reasons other than race. You're blinded by race.