Why did the South switch parties?

[All Along The Watchtower]

Basically, it was a combination of white backlash against the Civil Rights Act of 1964, increased levels of income and wealth, a corresponding increase in the population of metropolitan areas at the expense of rural areas (with Northern white conservative migrants making a fairly significant contribution here), the  transformation of white racial attitudes from being openly racist to being more "colorblind" in light of whites believing that civil rights issues had basically been "solved" and thus, whites being opposed to the expansion of civil rights protections against de facto segregation and inequality (as opposed to de jure segregation and inequality), the decline of the white populism of  the downtrodden in favor of the white populism of the upwardly mobile middle class and aspiring middle class, the rise of the Religious Right - which made the white evangelical Protestants who dominated Southern culture a political force to be reckoned with -, generational replacement (how many Southern whites who are alive today remember the New Deal? lol), and finally - as Torie alluded to - the Voting Rights Act precipitating the collapse of the white Democratic machines that had made the South effectively a one-party region (with their collapse creating an actual two-party system in the South in which black voters were increasingly influential within the region's Democratic Party).