Democratic forum-debate and why is the South so Republican?

At the November 6, presidential "debate-forum", nicely hosted/moderated by Rachel Maddow, in South Carolina, the former Maryland Governor Martin O'Malley was why Republicans are so dominent throughout the Southern states?  In other words, it's hard for a person to identify as a Democrat in Southern states and, consequently, more difficult to win elections, unless the candidates are registered Republicans.

Governor O'Malley represented a "southern state", said Maddow. Obviously, Maryland is geographically on the southern side of the dividing US Mason Dixon line. 

As a native, I grew up in Maryland and lived for most of my formative years in Baltimore and Baltimore County, so I was unhappy to see my home state identified with the political demographics of the American south. When I grew up, Maryland was considered to be a "border" state meaning it was neither northern or southern. Also, Maryland was one of the original 13 American colonies and the first Catholic settlement established by the influence of Britian's Lord Baltimore. 
Nevertheless, it was posed to Governor O'Malley to explain how it is the American South has become so overwhelmingly Republican.

At one time, prior to the Civil Rights Movement against segregation in the 1950s and 1960's, the American southern states were predominantly Democrat. It's been reported, when President Lyndon Johnson signed The Civil Rights Act in 1964, he knew the political consequencesof the law, but he underestimated the generational impact.  

"We have lost the South for a generation,” is what Johnson was reported to say. Unfortunately, the Southern political response has gone on for much longer than Johnson could've imagined. Here we are in 2015, and the South is entrenched in fundamentalist right wing Republican politics. Regardless if the story about Johnson's quote is true or not, the fact is, a reaction to Johnson’s act of courage, turned the south Republican.

Perhaps, Maryland 40 years longer than the others to join the South because Governor Martin O'Malley's successor turned the state's leadership Republican.

But, I've seen Maryland go briefly Republican in the past. Governor Spiro Agnew was a prime example.  Governor Robert L. Ehrlich was a one term Republican.  Now, the recently elected Republican Governor Hogan appears to be a one termer as well, because he's been diagnosed with a malignant illness. After issuing an executive order, reducing the toll on the Chesapeake Bay Bridge, it appears Governor Hogan hasn't been well enough to launch much political momentum.

I believe the South is predominantly Republican because our nation abandoned these states after the Civil Rights Act became law.  

In fact, few if any had the political gutzpah to create an environment where the civil liberties of Negroes was protected and their social institutions were supported.  In fact, the Civil Rights Act was a band aid to a help heal a terrible racial divide in the South; but after the scab was ripped off the wound, there were few interventions to create confidence and trust among those who were highly skeptical of the US governmnents' enforcement of this law.  

It may be too late in our generation to turn the South around and create confidence in the government's Civil Rights inverventions on behalf of protecting people against racial discrimination.  

Yet, we must applaud Rachel Maddow for asking the salient quesiton and for giving this important issue a forum for discussion at the wonderfully moderated Democratic forum/debate. There were a lot of supportive people in the South Carolina debate audience. Indeed, "hope springs eternal".