Carter won the South in the 1970s. Clinton won some of the South in 1992 and more of it in 1996. 1976 1992 1996
At the 1964 Democratic convention (which was fascinating to watch on TV), the Mississippi delegation walked out because they'd been replaced by an integrated delegation. That was the beginning of the South questioning Democrats. The change was all talk about 1965-75, then surged while that smiling Southern gentleman Reagan was President. It's like the (heterosexual) sexual revolution. Premarital sex was mostly just talk in the 60s (novels, movies, other media), but people (radical young long hairs) actually started living together unmarried en masse in the 70s, and by the 80s it was default to live with people of the opposite sex a few years before marrying them. Obviously there were many exceptions, but the idea is that a social change is all theory for a while, then it's all talk in the media for a decade, then radicals do it for a decade, then it becomes default and mainstream.
OK, I read the article. A former GOP staffer parrots every Dem talking point and gives a few examples from backbenchers in order to paint an entire political party. I suppose if a former Dem wrote a similar article and referenced kooks like Alan Grayson or Anthony Weiner, it would prove something as well? What was the point of posting an opinion piece and trying to stereotype an entire population of people with it? Seems like a rather GOP thing to do, IMO.