This public broadcasting site has a historical timeline of political broadcast advertising. The site also breaks down, in detail, how candidates develop ads -- from the mechanics to the background research.
"This Internet site is part of the Annenberg Public Policy Center's on-going research into issue advertising. On this site you can find reports on issue advertising, and profiles of organizations that aired issue-ads in 2001 and 2002. This site also contains estimates of the amount of money spent on legislative issue advertising in the nation's capital for the years 2001 and 2002, coinciding with the 107th Congress."
An anti-Bush site sponsoring a contest for producing the best negative advertising about President George W. Bush. Seven reasons are listed to oppose Bush. The ads of the 26 finalists are displayed on the Site.