I agree that you can't make any blanket statement about the politcs of people who like folk music. The first place I heard Leadbelly was at the house of a childhood friend. His father was rumored to be a John Birtcher and in '68 he worked for George Wallace. When he felt liberal he voted Republican. But he loved Leadbelly. The only point being that people are too complex and unpredictible to pigeonhole.

I, for example, love folk music and I don't even own a pair of Birkenstocks! (not a Republican though)