A year after I was born, LBJ signed the Civil Rights Act, turned to an aide and said, "We have lost the South for a generation." He was being optimistic. After all, Southerners had, up to that point, stuck with the Democratic party for no other reason then that the winner in the War Against Northern Aggression was a Republican - and they weren't going to forgive that, even if 100 years had passed.
Back then, being a Republican meant something quite apart from what it means today: your average Republican was generally a reasonable person, economically conservative but socially liberal, well educated and very intellectual. They represented the ruling class, but compared to today's nut jobs they did it relatively well, and at least begrudgingly accepted that social spending was necessary to keep the system from collapsing into class resentment and rebellion.
Nixon seized on the rift created by LBJ with his Southern Strategy, bringing a more reactionary element to the Republican tent. This Southern element began pushing the GOP further to the right. The Birchers and the fundamentalists gained ascendancy. As this shift progressed, the intellectual old guard began to look for a way out. They switched parties. They, in turn, pushed the Democratic party rightward. Thirty years of feedback loop later we have, in effect, an extremist, fascist party, the GOP, and a right wing party that would make your average Republican from 1964 blush - The Democratic party. And the leader of that party, Barack Obama, is to the right of Richard Milhous Nixon on every issue you can name. The Left has no voice at all in the party machinery.
Which is where all the confusion lies. When our current President doesn't stand up for the middle class or when he fails to fit the mold of a "democrat' it is because he isn't one in the sense most people mean when they say "democrat". His spine has nothing to do with it. He is a Republican, or more precisely, if this were 1964, he would be a Republican, and a very conservative one at that.
LBJ once said, "No member of our generation who wasn't a Communist or a dropout in the thirties is worth a damn." Change the decade and apply it to our current President - he simply isn't worth a damn.