I love it when people ignore the complete polar shift in social ideologies between the parties that happened in the middle part of the last century. Particularly because the poster Simon was replying to specifically singled out "conservatives" and "liberals" - ideologies, not parties. Yet Simon, in his reply, ignores that and immediately tries to shift it to "Republican" and "Democrat" - meaningless designations without the context of ideologies. It's one of the most intellectually dishonest debate tactics you'll see conservatives use when they get uncomfortable with discussing past positions that conservative viewpoints espoused.
Yes, the South, for a very long time, voted Democrat, and Lincoln was a Republican. Is everyone just going to ignore that, when LBJ picked up the Civil Rights movement as a Democratic platform, that the Republicans swooped in to picked up disaffected bigots in the South? The Democratic party shifted far more socially liberal over the next couple decades, while the Republicans went the other direction, embraced the bigots who didn't like that the Democratic party had shifted underneath them - particularly on issues like giving blacks equal rights - and strengthened their base substantially.
Interestingly enough, religious objection to abortion wasn't quite a major thing until right around the same time - the late 60s and early 70s. Even evangelical views on it were varied and complex, until the so-called "Moral Majority" solidified and weaponized it as a wedge issue to drive voters to the polls.