Americans warmed to President Obama in early 2012, giving his job approval rating a raise and significant leads over Mitt Romney and Rick Santorum in most recent polls. His improved outlook owes to a better economic picture, but a perennial bugaboo threatens to erase those gains and weaken his chances at reelection: spiking gas prices.

Gas prices have jumped 29 cents per gallon since December, according to the Energy Information Administration (EIA). Rising gas prices drain economic confidence fast, as most Americans feel pinched as soon as they fill up their next tank.

How much do gas prices matter? Rising oil prices drag down consumer spending, according to Economist Yash P. Mehra and associate Jon D. Petersen, a key indicator that was on the rise in January. And while other economists find limited impact on the overall economy, consumers are widely aware of gas price spikes and notice the lighter wallets. As fuel costs peaked in 2008, fully 77 percent of Americans in a Washington Post-ABC News poll said the price increases caused financial hardship in their households. Over half the public reported serious setbacks.

The trend may continue. Crude oil prices jumped to a nine-month high Monday as Iran blocked exports to Britain and France. Continuing tensions in the Persian gulf don’t bode well for relief at the gas station.

The EIA releases its latest measure of gas prices at 5 p.m. today.

Today’s poll bits

Obama’s week in approval — Obama holds a 44 percent approval rating in the latest Gallup tracking poll, with 48 percent disapproving. It’s near his worst mark in February, though only a slight reversal from a week ago (46 percent approved, 47 percent disapproved). Most media polls so far in February have shown Obama riding an upswing.

Tight GOP races Michigan, Arizona — The latest polls show Romney and Santorum within a few points of each other in both of next Tuesday’s contests. In Michigan, each candidate posts a numerical but statistically insignificant lead in automated polls from the Republican firm Mitchell Research/Rosetta Stone Communications and Democratic Public Policy Polling (PPP). In Arizona, Romney and Santorum are three points apart in a PPP poll released Monday. Neither firm calls cell phone-only voters, which adds another factor of uncertainty in the current state of the race.

Note: An earlier version of this post incorrectly stated Obama’s approval in the Gallup poll was his worst in February. His worst mark this month was 43 percent in interviews completed February 15.

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