The cost of a gallon of gas kept rising last year, but not at the torrid pace of 2010 and 2011. That helped keep inflation in check. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

Motorcyclists Hanna Gilan, right, and her son Chaim Gilan fill up their Vespa scooters with less than two gallons at a gas station in the Echo Park district of Los Angeles on Oct. 4, 2012. Damian Dovarganes/AP hide caption

itoggle caption Damian Dovarganes/AP

President Bush and then-Democratic presidential nominee John Kerry shake hands at the end of a presidential debate in 2004 in St. Louis. Researchers want to better understand why partisans' views of the facts change in light of their political loyalties. Charlie Reidel/AP hide caption

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President Obama announces support for building an oil pipeline from Oklahoma to Texas, Thursday in Cushing, Okla. Tom Pennington/Getty Images hide caption

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A driver pumps gas into his Toyota Prius hybrid at a gas station in Sunnyvale, Calif., in 2007. Paul Sakuma/AP hide caption

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How big a role do U.S. presidents really play in controlling gas prices? Prices were well over $4 a gallon in La Jolla, Calif. on March 8. Mike Blake /Reuters /Landov hide caption

itoggle caption Mike Blake /Reuters /Landov