It worked in his presidential primary contest against New York Sen. Hillary Rodham Clinton when she proposed a "gas tax holiday" for the summer, a pitch he opposed despite its popularity with many voters. But that was in April before gasoline shot past $4 a gallon.
Virtually all polls now show dealing with energy prices high atop the agenda of voters.
At issue for Obama's Republican opponent, Sen., is opening up offshore drilling to boost production, a move McCain and others GOP lawmakers say would increase supply and help control soaring gasoline prices. Opponents, including Obama and many other Democrats, say new offshore oil would be years away from reaching consumers and even then would make little difference in prices and the ongoing U.S. need for foreign oil.
Republicans clearly have targeted energy prices, looking to boost their standing with consumers. President Bush has pushed Congress to permit the offshore drilling and warned that "the American people are rightly frustrated" because Democrats won't allow a vote on opening up offshore drilling.
For his part, McCain has his sights squarely on Obama's opposition to offshore drilling, labeling him "Dr. No when it comes to energy production." The tactic is not surprising, because polls have shown that consumers - even in environmentally sensitive states like Florida - are desperate for politicians to do something about energy and favor offshore drilling by big margins.
Obama is pressed on the issue repeatedly on the campaign trail, but he refuses to budge, preferring to take pains to spell out his reasons.
"Please be in favor of offshore production," Steve Hilton, a retired federal government worker in Lebanon, Mo., implored Obama during a tour of a diner there Wednesday.
"I'm in favor of solving problems," Obama responded. "What I don't want to do is say something because it sounds good politically."
Obama seeks to turn the issue on its head, arguing that McCain and Bush are practicing the old politics of simply promising people something that's symbolic without addressing the real problem. Discounting drilling, he proposes energy rebates, a crackdown on oil speculators who manipulate the market and a renewed focus on energy alternatives.
"Instead of offering any real plan to lower gas prices, Sen. McCain touts his support for George Bush's plan for offshore oil drilling," Obama said Thursday in Cedar Rapids, Iowa. "But even the Bush administration acknowledges that offshore oil drilling will have little impact on prices. It won't lower prices today. It won't lower prices during the next administration. In fact, we won't see a drop of oil from this drilling for almost 10 years."
Adding their own take on the debate are the Sierra Club and MoveOn.org, which announced Thursday that they will air ads criticizing McCain's call for expanded oil drilling and tax proposals that would benefit oil companies. The MoveOn.org ad depicts a man speaking to the camera complaining that McCain's proposal to lift a moratorium on energy exploration on coastal waters won't produce oil for years. "That's not a solution Mr. McCain, that's a gimmick," he says.
In fact, McCain opposes drilling in Alaska's Arctic National Wildlife Refuge, and during his 2000 presidential run opposed lifting the offshore drilling moratorium as well.
Although Obama makes the argument against offshore drilling much as he did against Clinton's gas tax holiday, he faces a tougher challenge now. The disagreement with Clinton was played out in front of Democratic primary voters, many of them closely following the race and its issues.
The argument with McCain comes before a general election electorate as frustrations over gasoline prices grow at the height of the summer driving season and as the nation prepares for winter and heating costs. Polls suggest a lot of voters are pressing for politicians to do anything, even if it's symbolic.
Voters in New Hampshire and other states hit hard by winter feel especially pinched by high fuel prices. Many homeowners enter into winter heating oil contracts during the summer.
"It's on people's minds," said Fergus Cullen, state GOP chairman in New Hampshire, where the cost of heating a typical suburban home has doubled since last winter, to about $5,000. "The issues that people care about have changed dramatically since 2006 here and, not incidentally, in a way that is beneficial to Republican candidates."
Adding to that pressure, Obama will face the full force of the GOP and the McCain campaign. To counter it, Obama cited Exxon Mobil's record profits - the company on Thursday reported second-quarter earnings of $11.68 billion, the biggest ever by a U.S. corporation - while contending that the GOP candidate's plan for offshore drilling won't help consumers and "reads like an oil-company wish list."
Obama concedes that crossing the public mood on energy prices could be risky - and he's right. Though the public has largely turned against a war in Iraq that McCain fervently backs and Bush's popularity is at record lows, polls show the election remains tight, with Obama clinging to a small lead.