I believe it was a story posted on this site earlier explaining the drop in prices were due to a shift from summer to winter blends and that winter blends were cheaper.

I linked to my post on winter gasoline in the above essay. In fact, winter blends are cheaper to make, and the transition happens a couple of months prior to the elections. Further, the elections happen well after peak driving season. That's why prices usually fall after peaking in late spring/early summer - election year or not.

Here is the summary of gasoline prices for the past 19 years. The value for the first Monday report in the calendar year is set to a value of 1.00.

Average Gas Prices

The value for each subsequent week is calculated relative to this value. As can be seen, the gasoline prices, on average, rise rapidly through the first half of the year, stabilizes during the summer driving season with some slight declines after the fourth of July and then begin to fall about 4 weeks before the first week in November. Oil prices have much more volatility but also show a similar average trend.