I believe that "libertarian voters", according to Rasmussen's classification, are
not self-described libertarians, but rather "fiscal conservatives and social liberals." So they are a group defined by the
pollster, not themselves. That likely explains their surprising preference of presidential candidate. In my personal experience, the large majority of people who describe themselves as "libertarian" are more concerned about economic than social issues, and you will almost never come across a Democrat in libertarian circles.
BTW, it's also surprising that Bob Barr doesn't even register in Rasmussen's poll, even among the group they define as "libertarian."
yea, i bet you’re right, that’s probably what happened. People, i guess, have different ideas on what it means to be socially and fiscally conservative.