I think one answer is that you have a rather large generation seeing their era end. I'm not engaging in generational bashing here, just suggesting that there are some clear cultural changes which, while they don't quite rival the changes that happened around the 50s and 60s, still signal to people that Things Have Changed. Reagan and the rise of the Christian Right put the brakes on certain changes. We stuck with Archie's world a bit longer than we would have thought, but now it's an updated version of Meathead's world.
A somewhat older woman was chatting with me at a bar during brunch the other day, and that "lifelong Democrat turned Republican" had some incoherent remarks about why 2008 changed everything. But, basically, it was hard to hear what she was saying as anything other than "younger African-American guy is president this is somehow wrong why are all the kids on my lawn."