Libertarians
I'm always concerned that my impassioned disdain for libertarianism stems from the time someone I was dating spurned me for a Mises-worshiping jackhole, but then I see posts like this and figure that no, it's just because libertarians really are the worst.
I knew a pretty progressive girl in college who voted libertarian, and I was shocked. I asked her why and she said, quote: "Aren't they, like, for the constitution and liberty?"