One of the little known facts about the reclusive cartoonist behind "Calvin and Hobbes" is that he used to be an editorial cartoonist. In addition to his 6-months stint at Cincinnati Post, he also drew for the Sun Newspapers chain.
Bill's editorial cartoons are hard to find, except for two posted here. However, fairly recently, blogger Matt Tauber is posting some of his editorials. It came from microfilm, but these are probably the best we have for now. See one here and here.