Underlying factors may mean more in the presidential race than the day-to-day food fights and spats about this and that. For example, see Chris Cillizza's column in The Washington Post which focuses on two key charts.
The first chart shows consumer confidence which, after improving until May, has dropped back as low as it was in January. The second chart shows the relation between consumer confidence and whether incumbents got reelected. On it Obama is clustered with the losers: Carter and Bush I. All the winners are at the other end of the spectrum, where the consumer confidence is higher.
