Whenever the Republicans lose an election, they blame it on "RINOs", since no person would actually cast an informed vote against a Republican. Whenever the Democrats lose an election, they blame it on the stupidity of the voting public, since no person would actually cast an informed vote against a Democrat. It's a very old pattern that found expression during the Bush election with the famous "Jesusland" map, as well as maps comparing the red versus blue states to the maps of the War Between the States. Since the current electoral results show Democrats losing, it is worthwhile to rebut one of the claims of how they unfairly lost.
The most insidious explanation for Democrat losses is "the Southern Strategy", which is a severe insult against all Southerners as ignorant racists. It is one of the most hyped theories around, but it is not a given that it even exists. It traces to the musings of one Republican who was a racist, but doesn't trace to any actual proof that any actual strategy even exists in the first place. All evidence for it is circumstantial - that since the late 60s the Solid South stopped voting Solid Democrat and started voting Republican a lot more often.
The Southern Strategy is allegedly based on the Civil Rights Act of 1964 and the fact that it was signed by a Democrat president, even though it was put on his desk because Congressional Republicans pushed it through. Key votes are examined such as when Goldwater voted for every Civil Rights Act before the 1964 one, and key votes are ignored such as when Goldwater's opponents voted against every Civil Rights Act before the 1964 one.
The theory states that because a Democrat president signed the Civil Rights Act, the ignorant and racist South turned Republican. The facts do not support that assertion.
Democrat Jimmy Carter's won victories in every Southern state except for Virginia and Oklahoma in the 1976 Presidential election, years after the alleged emergence of the Southern Strategy.
Democrat Bill Clinton was able to win five southern states twice (Louisiana, Arkansas, Tennessee, Kentucky, West Virginia) and two states once (Georgia in 1992 and Florida in 1996). Virginia, Texas and North Carolina were won by the Republican candidates by significantly smaller margins than usual.
The first Southern state to give the GOP control of both its governorship and its legislature was Florida. It did not do this until 1998. Florida has an atypical population for a Southern state, with a large retiree population from northern states and also a large Cuban population that leans Republican due to a shared opposition to Fidel Castro.
Georgia did not elect its first post-Reconstruction GOP governor until 2002. Until 2005, Louisiana had been represented since Reconstruction only by Democratic Senators. Arkansas has two Democratic Senators, a Democratic governor, three out of four of their U.S. representatives are Democrats, every statewide office is held by a Democrat, and their state legislature is Democratic. Tennessee and North Carolina have a majority Democratic delegation in the U.S. House of representatives. Mississippi has a house delegation that is evenly split between Democrats and Republicans.
It seems that the "Southern Strategy" which is quoted so often is more the musings of one particular racist Republican and not a Republican Party policy. Nixon is supposed to be the epitome of the evil American politician, but he is still just one person.
What caused the South to shift from Solid Democrat to mixed?
In the 1970s the Moral Majority was actually a factor. Its leaders endorsed the Republican Party, and it morphed into the modern phenomenon of the Religious Right. The South, being the home of Southern Baptist fundamentalism (a whole different creature from Puritan fundamentalism), was wooed into the Republican Party that way.
Another factor is Air Conditioning. One of the reasons heavy development didn't occur in the South is the fact that it gets hotter there in the summer than it does in the Rust Belt. It's easy to heat a building; it's harder to cool it. Couple the widespread use of Air Conditioning with the fact of overly-strong pro-union legislation in Northern States, and the result is that many businesses become willing to relocate to the South, and people moving there along with the businesses. The South has experienced population growth above and beyond that of other areas in the country - and that is not due to a birth rate but immigration from other states.
Plus the Republican Party has done a better job of appealing to the "common man." The Democrats appeal to the lower classes is more to the "down and out". The "common man" works for a living, the Democrats campaign towards those who live off of government handouts. When Reagan played "Born in the USA" at the 1984 Republican Convention, it was a strategic coup, because it identified the GOP with those who work hard all day then kick back with a beer to relax while watching a game on television. The Democrats, when not identified with the lowest class, identify with New England wine drinking elitists.
New England is one more reason that the Solid South fractured. The elitism of New England has never gone away, and the disdain New England feels for the South is matched only by the resentment the South feels for New England. One side still resents the abuses of reconstruction. The other side still resents that an entire region of the country dared question the doctrine of central authority. When the Democrats embraced New England, they sundered themselves from the South. Even as late as 1996 Georgians were worried that during the Olympics that the liberal elitist journalists would come down from the North, look for the absolute worst and most backwards parts of Georgia, and send back images saying "This is Georgia today." It's like going to a mansion and only photographing the angst-ridden teenager's bedroom.
Puritan Fundamentalism no longer exists in the form it did back then. It still exists, but in a secularized way. Instead of trying to create God's Kingdom on Earth, ruled over by pious Elites, the modern Democrats try to create a Socialist Utopia on Earth, ruled over by Elites. One look at the Hillary Clinton's 2008 campaign shows this tendency. There wasn't a single position that she took in her entire campaign that wasn't "I know best about everything in your life and if you give me absolute power I will create a secular God's Kingdom on Earth."
Religion, industry, air conditioning, elitism, the difference between the common man and the downtrodden masses, many things went into the fracturing of the Solid South. Blaming it all on the words of one racist Republican is terminally short sighted to a degree that it can only make sense if someone desperately wants it to be true, but not in any actual analysis. What that really proves is that the south is not solid in either direction. Any remarks about how the Civil Rights Act did this are little more than sour grapes, saying "how dare those ignorant racist southern rednecks not deliver the vote for us like they should."