I'm gonna have to go look for a chart of pump prices vs. barrel prices in late 2004. Did oil companies suppress the retail price to help his re-election?

I'm not sure about this. I don't think that petrol prices can be said to be the cause of (dis)approval. Rather, petrol prices and disapproval are both indicative of world events and short-term global stability.

World events like Bush's policy and actions, those world events?

Bush policies are heavily influenced by his experience as an oil independent -- all of whom prosper during high oil prices and suffer during low oil prices.

The relationship between the independents and the majors is nicely described in The Prize.

Yes, but also increased demand for oil, Nigerian resistance, and Iranian ambitions. However, surely people aren't as superficial as to approve of US foreign policy, provided oil prices are low?