Last night, Bill O'Reilly encouraged Mitt Romney to hammer President Obama over gas prices. But in 2008 O'Reilly was singing a different tune, correctly saying that “it's complete B.S.” for politicians to claim they will bring down oil and gasoline prices.

Fox News contributor Karl Rove reassured O'Reilly that his SuperPAC is running false advertisements on this very subject. The network has aided Rove's efforts by repeatedly airing a misleading graphic that implies President Obama is to blame for rising gasoline prices, and claiming that Americans are worse off than they were four years ago. But as The Wall Street Journal has previously noted, gas prices are “largely fixed by the price of crude oil, which is determined by global supply and demand,” and "[w]hen Mr. Obama was inaugurated, demand was weak due to the recession. But now it's stronger, and thus the price is higher."

Earlier this year, PolitiFact rated a similar claim “mostly false” partly because it failed to account for seasonal gas price fluctuations between winter and summer -- a factor Fox News also ignores. While oil production has risen under the Obama administration, experts say that increasing drilling in the U.S. won't lower gas prices. But by reducing our dependence on oil, including by raising fuel economy standards, we can reduce the American economy's vulnerability to price spikes.