Catching up on my Time magazines and they had a stat about voter groups in a recent issue. 40% of Americans now identify themselves Independents with most of them leaning to the left on social issues and to the right on taxes/spending.
This may be an even more extreme simplification, but you could say libertarians fall into the "old, crazy/drunken uncle" catagory... you know, the uncle that everyone tries to avoid at a family reunion. It might be entertaining to watch from a distance as he stumbles about, ranting at everything, but no one is really interested in hanging around him.
Ted Kennedy was a Libertarian? Who knew! Heck, VP Biden must be a Libertarian too! And good ole Uncle Willy C. fits the 'bill' also come to think of it! And here I thought there weren't any Libertarians who had made it to higher offices. I don't think I can include the current President, though. I don't get the impression that alcohol was ever his drug of choice.