The Left loves to smear the Right with cries of racism, but when the Right points out that it's the Democrats who are the party of slavery, segregation and Jim Crow, the Left always reverts to the claim that both parties "switched" following the passage of the Civil Rights Act, and uses the fact that the South is now consistently won by Republicans somehow as "proof."

The South is now a Republican voting bloc — but not because of the mythical party switch.

Vanderbilt University Professor Carol Swain explains in PragerU's latest video that there are three myths behind the myth that both parties switched after the Civil Rights Act passed.

The first myth is that the Republican Party only began to win the South when they started to pander to Southern white racists in the 1960s, when in fact Republican presidents Herbert Hoover and Dwight Eisenhower won Southern states prior to the 1960s. And, just as a reminder, the Republican Eisenhower is known for sending the 101st Airborne Division to Little Rock, Arkansas, to uphold the Supreme Court's decision to de-segregate schools, against pushback from Democrats. The truth is Republicans were able to win over many Southern voters prior to the '60s without "pandering to racists."

The second myth is that segregationist Democrats bolted to the Republican Party after the Civil Rights Act was passed. In actuality, 20 of the 21 Democrats who voted against the Civil Rights Act remained Democrats and their seats remained in Democratic hands for over 20 years. (PragerU breaks down all the specifics in the "Facts and Sources" section.)

The third myth is that the Republican Party has maintained a stronghold on the South with their use of the so-called "Southern Strategy."

"Richard Nixon, the man who is often credited with creating the Southern Strategy, lost the Deep South in 1968," said Swain. "In contrast, Democrat Jimmy Carter nearly swept the region in 1976 — 12 years after the Civil Rights Act of 1964. And in 1992, over 28 years later, Democrat Bill Clinton won Georgia, Louisiana, Arkansas, Tennessee, Kentucky and West Virginia."

Swain added, "The truth is, Republicans didn't hold a majority of southern congressional seats until 1994, 30 years after the Civil Rights Act."

Rather than the offensive allegation in the Democrats' convenient, racially-charged narrative, the Republican stronghold in the South today is grounded in the fact that over time, racism has dissipated in the South while conservative values have gained more and more traction.

"In short, history has moved on," said Swain. "Like other regions of the country, the South votes values, not skin color. The myth of the Southern Strategy is just the Democrats’ excuse for losing the South, and yet another way to smear Republicans with the label 'racist.'"

Watch the full video below:

Follow Aaron Bandler on Twitter.