Racists remained, switched from Southern Democrats to Republican.<quoted text>
The old Southern Democrat mentality died off. After the passage of the Civil Rights Act of 1964 of which they vehemently fought to keep from passing, their racism no longer had any muscle.
Many blacks fled the southern states before the 1960s and many northerners moved into the southern states before the 1960s.
By 1968, the south represented the rest of the nation. The racist Southern Democrat bloc no longer existed.