Great...lets have a look at this "actual party switching" shall we? And lets see what actually holds up to critical analysis.
The story is based on three claims: 1. The Republican were weak in the South and to become competitive, began to appeal to racist (aka The Southern Strategy). 2. Southern Democrats switched parties after the 1964 Civil Rights Act. and 3. Since the "switching" the Republicans became the dominant party in the South.
The first claim (like the all three claims, is a myth) is incredibly ignorant. The Republican Party was competitive in the South going back to the 1920's. Hoover (Republican) dominated the South in the election against Democrat Al Smith, Hoover took 47% of the Southern Popular Vote. In the 1950's, Eisenhower was incredibly popular in the South, winning the states of TN, FL and VA in 1952 and LA and KY in 1956. That came after Ike supported Brown vs The Board of Education and his sending of the army to Little Rock to desegregate the local high school.
As we can see, the claim that Republicans were not competitive until "pandering to racists" in the 1960's is historically inaccurate.
The second claim, and the key argument, is that the Civil Rights Act of 1964 caused a major shift in the parties, with elected Democrats moving to the Republican Party. Does this hold up? NOPE. There were 21 Democrat Senator's who opposed the Civil Rights Act of 1964. How many switched parties in the 1960's after that? Well that would be the overwhelming number of ONE!!! One person, and the remaining seats continued under Democrat control for next 20-30 years.
If there was such a major "switch" of voters supporting racist Democrats to racist Republicans, its odd they waited until the late 1980's into the 1990's to finally set control of the South with the Republican Party.
Claim 3, since the Southern Strategy, Republicans (aka racists) have dominated the South. Again, history is not kind to false claims. Dick Nixon, who is credited by Democrats as the creator of the Southern Strategy, LOST THE SOUTH in 1968 (fours years after the Civil Rights Act) and Carter all but swept the region in 1976 (Twelve years after the supposed racist in the Republican Party became dominant). And in 1992, Bill Clinton won six Southern States. Then, the so-called solidified racism in the South, went on to elect black man Senator Tim Scott in 2013.
Yes, I know, history books tell you these claims are true, and we have never seen bias in education.