Going back to an earlier question about why much folk music has a left-wing bent, it seems to me that folk music is inherently populist. That is, it is music about the lives of ordinary people, working people, and generally expresses respect for and faith in "just plain folk." And a corollary to that is the populist distrust or disdain for large organizations, bureaucracy, authority, elitists, upper class twits, bosses, the rich, corporations, phonies, people who "straddle a fence, as only a eunuch can" (why am I suddenly thiking of Bill Clinton?), liberals who are devoutly liberal "as long as it doesn't cost them money, or affect them personally" (sorry for not getting the quote right, Phil), etc. Those fundamentally populist sentiments can be directed also at Big Government and brief-case toting bureacurats, in which case they take on a more right than left wing cast, or at least anarchic. Somehow it seems that those on the right, when they get mad, are less likely to burst into song.
It also seems to me that the Right has been doing a much better job of tapping into these populist sentiments lately than has the Left (if there is one) or the Center, which is unfortunate because it means we then get populist rhetoric in support of policies that are fundamentally against the interests of the common people.