No Mustache Rides in the White House

This is Bob Barr. He's running for president. Of the United States. As a Libertarian. The Libertarian thing alone will ensure that he won't be elected , but there's also the issue of the mustache. No president since William Howard Taft has had a mustache (or facial hair of any sort), and he left office in 1913. Thomas Dewey and his crumb catcher camethisclose to being elected in 1948, but clean shaven Harry Truman, contrary to what the Chicago Tribune thought, prevailed. We, the people, apparently like our presidents whisker-free. Why is that? I'm sure there's a psychological reason of some sort, I just don't know what it is.