My daughter showed me this site, and having just come through the 2004 election cycle, I found it very interesting. It's the American Museum of the Moving Image. On their site you will find all the major Presidential campaign commercials from about 1952 to present. It's a fascinating look at history, and a chance to put a face to some of the obscure names from Presidential campaigns of the past (Adlai Stevenson and Estes Kefauver, anyone?).
Not only that, but I noticed just how similar the problems of the past are to the problems of today. The more things change, they more they stay the same.