With the record sums being spent on presidential campaign advertisements, we really need to be 'On Message.' Fortunately, E. D. Dover's excellent new study gives us the means to follow the flurry of campaign commercials from the 2008 nomination and general election campaigns. From the earliest ads in the smallest caucus markets to the national ads of early November, On Message gives us a thorough report and a thoughtful analysis of how two crowded fields of presidential candidates introduced themselves and sold themselves to voters throughout that pivotal election year.