The Republican Party, of course, was founded in 1848 with the abolition of slavery as its core mission. Almost immediately after its second presidential candidate, Abraham Lincoln, won the 1860 election, Democrat-controlled southern states seceded on the assumption that Lincoln would destroy their slave-based economies.

Once the Civil War ended, the newly freed slaves as expected flocked to the Republican Party, but Democrat control of the South from Reconstruction until the Civil Rights Era was near total. In 1960, Democrats held every Senate seat south of the Mason-Dixon line. In the 13 states that made up the Confederacy a century earlier, Democrats held a staggering 117-8 advantage in the House of Representatives. The Democratic Party was so strong in the south that those 117 House members made up a full 41% of Democrats' 283-153 advantage in the Chamber.

Likewise, throughout the late 1950s and early 1960s, Democratic governors and overwhelmingly Democratic State Legislatures controlled the South, which steadfastly opposed the push for civil rights. In contrast, Republican President Dwight D. Eisenhower, openly praised school desegregation in the Brown v. Board of Education decision and sent federalized Arkansas National Guard troops to Little Rock to protect nine black students after Democratic Governor Orval Faubus threatened to keep them out of a previously all-white high school.

Eisenhower was a phenomenally popular war hero when he was elected in 1952, and even though only one Republican had ever before won any southern states in the Electoral College (Herbert Hoover in 1928), Eisenhower began to make inroads for the Republican Party; winning Florida, Texas, Virginia, and Tennessee. In his landslide victory four years later, Eisenhower picked up Louisiana and Kentucky.

His personal appeal, though, didn't transcend the Democratic Party's hold on the South, and when he left office in 1961, that hold was arguably stronger than it had been in decades. As Southern Democrats clung to traditional segregation, though, the rest of the country was changing, and the push for civil rights had begun.

After the assassination of President John F. Kennedy--a strong proponent of civil rights--in late 1963, Southern Democrat Lyndon B. Johnson saw it as his mission to pass the Civil Rights Act as a tribute to Kennedy, who had first proposed the bill five months before he was killed. Democrats in the Senate, however, filibustered it.

In June of 1964, though, the bill came up again, and it passed...over the strenuous objections of Southern Democrats. 80% of House Republicans voted for the measure, compared with just 61% of Democrats, while 82% of Republicans in the Senate supported it, compared with 69% of Democrats.

Nearly all of the opposition was, naturally, in the South, which was still nearly unanimously Democratic and nearly unanimously resistant to the changing country. One thing that most assuredly didn't change, though, was party affiliation. A total of 21 Democrats in the Senate opposed the Civil Rights Act. Only one of them, "Dixiecrat" Strom Thurmond, ever became a Republican. The rest, including Al Gore, Sr. and Robert Byrd--a former Exalted Cyclops in the Ku Klux Klan--remained Democrats until the day they died.

Moreover, as those 20 lifelong Democrats retired, their Senate seats remained in Democrat hands for several decades afterwards. So too did the overwhelming majority of the House seats in the South until 1994, when a Republican wave election swept the GOP into control of the House for the first time since 1952. 1994 was also the first time Republicans ever held a majority of House seats in the South--a full 30 years after the passage of the Civil Rights Act.

From there, Republicans gradually built their support in the South until two more wave elections in 2010 and 2014 gave them the overwhelming majorities they enjoy today.

If this was a sudden "switch" to the Republican Party for the old Democrat segregationists, it sure took a long time to happen.

The reality is that it didn't. After the 1964 election--the first after the passage of the Civil Rights Act and the opportune time for racist Democrat voters to abandon the party in favor of Republicans--Democrats still held a 102-20 House majority in states that had once been part of the Confederacy. In 1960, remember, that advantage was 117-8. A pickup of 12 seats (half of them in Alabama) is hardly the massive shift one would expect if racist voters suddenly abandoned the Democratic Party in favor of the GOP.

In fact, voting patterns in the South didn't really change all that much after the Civil Rights era. Democrats still dominated Senate, House, and gubernatorial elections for decades afterward. Alabama, for example, didn't elect a Republican governor until 1986. Mississippi didn't elect one until 1991. Georgia didn't elect one until 2002.

In the Senate, Republicans picked up four southern Senate seats in the 1960s and 1970s, while Democrats also picked up four. Democratic incumbents won routinely. If anything, those racist southern voters kept voting Democrat.

So how did this myth of a sudden "switch" get started?

It's rooted in an equally pernicious myth of the supposedly racist "Southern Strategy" of Richard Nixon's 1968 presidential campaign, which was accused of surreptitiously exploiting the innate racism of white southern voters.

Even before that, though, modern-day Democrats point to the 1964 presidential campaign of Republican Barry Goldwater, who refused to back the 1964 Civil Rights Act as proof that the GOP was actively courting racist southern voters. After all, they argue, Goldwater only won six states--his home state of Arizona and five states in the deep south. His "States' Rights" platform had to be code for a racist return to a segregated society, right?

Hardly. Goldwater was actually very supportive of civil rights for black Americans, voting for the 1957 and 1960 Civil Rights Acts and even helping to found Arizona's chapter of the NAACP. His opposition to the 1964 Act was not at all rooted in racism, but rather in a belief that it allowed the federal government to infringe on state sovereignty.

The Lyndon B. Johnson campaign pounced on Goldwater's position and, during the height of the 1964 campaign, ran an ad titled "Confessions of a Republican," which rather nonsensically tied Goldwater to the Ku Klux Klan (which, remember, was a Democratic organization).