With gas prices climbing and little relief in sight, President Barack Obama is scrambling to get ahead of the latest potential obstacle to his re-election bid as no one seems more aware of the electoral peril than Obama himself.

"My poll numbers go up and down depending on the latest crisis, and right now gas prices are weighing heavily on people," he told Democratic donors in Los Angeles this past week.

In fact, Obama raised the issue unsolicited in a series of town meetings in Virginia, California and Nevada that were ostensibly about his deficit-reduction plan. And he made the gas spike the subject of his weekly radio and Internet address Saturday.

"It's just another burden when things were already pretty tough," he said.

As Obama well knows, Americans love their cars and remain heavily dependent on them, and they don't hesitate to punish politicians when the cost of filling their tanks goes through the roof.

Indeed, for presidents, responding to sudden surges is a recurring frustration.

"These gas prices are killing you right now," Obama said at Facebook headquarters in Palo Alto, acknowledging that many Americans can't afford new fuel-efficient cars and must drive older models.. For some, he said, the cost of a fill-up has all but erased the benefit of the payroll tax holiday that he and congressional Republicans agreed on last December.

On Saturday, Obama insisted in his radio and Internet address that the best answer is a long-term drive to develop alternatives to fossil fuel. He also renewed calls to end $4 billion in subsidies for oil and gas companies. "Instead of subsidizing yesterday's energy sources," he said, "we need to invest in tomorrow's."

Republicans contend that high gas prices are the inevitable result of an administration they accuse of stifling domestic drilling, and which placed new curbs on offshore exploration after last spring's disastrous BP oil spill.

"The administration has declared what can only be described as a war on American energy," said Senate Minority Leader Mitch McConnell.

"Obama is vulnerable on gas prices and the Republicans have and will exploit this as a wedge issue," said James Thurber, who directs the Center for Congressional and Presidential Studies at American University.

Legislative aides report House Republicans are considering a series of hearings and floor votes on measures to boost domestic oil and gas production when Congress returns from its Easter break.

Meantime, Obama has ordered his Justice Department to form a task force to look for fraud or manipulation in the oil markets. It will "root out" any abuses, he told a town meeting in Reno, Nev. The president is among those who've said the surging price for crude is caused by worries about political upheaval in the Arab world and increasing demand from China and elsewhere.

Still, Americans have a tradition of holding the party in power responsible for rising gas costs.

Obama's focus on the issue came as a New York Times/CBS News poll published Thursday found that 70 percent of the public believes the country is headed in the wrong direction. That followed a March AP-GfK survey reflecting widespread discontent over the economy, with just 15 percent seeing an economic improvement the previous month. Through the spring, Obama's approval numbers in several polls have slipped.

"Gas prices are a major factor in his slide ... along with unemployment and his talk about cuts and tax increases to deal with deficits and debt," Thurber said.

The national average price for a gallon of regular gasoline is currently $3.84, almost a dollar higher than a year ago. In many places, it's well over $4.

The gas price debate has a sense of deja vu to it, Obama notes. Vows to end dependence on expensive oil imports go back to Richard Nixon's "Project Independence", a 1973 response to the Arab oil embargo, and this has been a popular refrain by presidents of both parties over the last 40 years.

"Whenever gas prices shoot up, like clockwork, you see politicians racing to the cameras, waving three-point plans for two dollar gas," Obama said in Saturday's address. But when prices subside, those plans are quietly shelved.

Even calls to target price gouging have a familiar ring. When gas hit $3 a gallon in 2006, George W. Bush launched a probe, declaring Americans "don't want and will not accept ... manipulation of the market. And neither will I."

Seven months later, Bush took what he called a "thumping" in mid-term elections. Of course, other issues -- like Iraq -- played a big role. But Obama can't help pondering that example, and wondering what rising gas prices could do to his hopes for a second term.