Exxon Mobil and Politics

I don't like to get very political in here, but continuing the gratutious linkfest with Abnormal Returns (I can't help it, they have wonderful stuff almost every day) I am fascinated, and creeped out by this graph on Infectious Greed comparing Bush's approval ratings and gas prices.

Silly Correlation theories:
Dual, uncorrelated effects of a single, uncharted, independent variable (Gloom as independent variable):  People with gloomy expectations for the future drive more, pushing up gas consumption and elevating prices.  Gloominess also pushes down Bush sentiment.

Direct correlation effects between the two variables. (Bush approval as independent variable): People work off anti-Bush steam by driving fast.  Increased consumption tightens supply and drives up prices.