It's less clear that voters give a president credit when gasoline prices fall.
Michael Dimock, associate director at the Pew Research Center, suspects that voters won't exactly thank Obama for $3.75 a gallon gasoline. Still, it dulls a weapon that his presumptive Republican challenger, Mitt Romney, would like to use to unseat the president.
And Obama can look forward to further help this fall. After Labor Day, refiners can begin using cheaper ingredients to make gasoline because wintertime clean air rules are less stringent. That should push gasoline prices lower between Labor Day and Election Day, barring hurricanes that can disrupt supplies or other global events, says Kloza.
"History will be working on behalf of the Democrats," he said.
Wiseman contributed from Washington. AP Staff writer Charles Babington contributed to this report from Washington.
Jonathan Fahey can be reached at http://twitter.com/JonathanFahey .
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.