BTW this topic is basically about, how did all these counties become Republican?
The most significant factor which led to this change in my opinion was the dramatic leftward movement of the Democrats. Their hawkish Foreign Policy quickly turned dovish, they started supporting all of these fringe social groups and issues, and soon their value base more resembled a socialist state like the Soviet Union then America. I don't know when it started but it was first noticeable in the 1960's.
that's not to say that every Democrat or even every Democratic politician feels this way, but it has become the heart and soul of the National Party. They blame America for all the world's problems, they have a very noticeable contempt for traditional American values, and their only foreign policy instinct is to appease and talk regardless of how irrational the opponent it is. Regardless of what they say, it really don't like America that much and are constantly trying to change it.
the Republicans of today more closely resemble the Democrats of Franklin Roosevelt Day then do today's Democrats. And by a wide margin.