Bethany's comment highlighted for me something I had not explained well in my theory of fashion in politics. I am including long-term fashions, trends, if you will, as well as the ephemeral Monkees/BSB/1D variety. Deep fashion, if you will, more in line with the fashion she notes in which areas of the brain it is now considered sexy to study. In the 1940's and 50's and into the 60's it was more fashionable to be accepted into the mainstream of American culture, and one can observe the strivings of the outsiders to cement their place. Since then, it has been more fashionable to be a bit outside - sometimes extremely outside, but not very often, and not among many. These days, to be a bit different in some way is the ticket.
It isn't an either-or proposition. There has always been a cultural tension in Western society between being one of the accepteds versus being one of the rebels, and I doubt it ever goes farther than 60-40 in either direction. Assortive mating is a strong controller to keep both in play. But by the fashionableness of Democrats, I don't merely mean the Obama Rock Star campaign stops (though I will include those as well), but the anti-fashion fashionableness of those who think themselves far above such plebian excesses.