(CNN) -- Sens. Hillary Clinton and John McCain are pushing for a gas-tax holiday, but Sen. Barack Obama says the plan is a quick fix that would do more harm than good.
Sen. Hillary Clinton campaigns this week in Wilmington, North Carolina. Gov. Mike Easley has endorsed her.
McCain, the presumptive Republican nominee, was the first to propose a temporary suspension of the federal gas tax.
His plan would lift the 18.4 cents per gallon tax during peak summer travel months. It also would suspend the 24.4 cent diesel tax.
Clinton, who rejected a similar idea in 2000, said her plan is different from McCain's. She said the Republican's proposal would cost the government up to $10 billion -- money that is used to improve roads.
The senator from New York said she'd make up for the lost revenue with a "windfall profits tax" on oil companies, meaning their profits over a certain amount would be subject to a 50 percent tax.
Her plan also would close $7.5 billion in oil and gas loopholes as well as monitor prices for manipulation. Watch how candidates plan to deal with soaring gas prices »
Obama does not support a suspension of the gas tax, which he described as a political scheme that would save the average driver $25 to $28.
"It's typical of how Washington works -- let's find some short-term, quick fix, even though we're not really doing anything," he said. Watch an analysis of how the candidates' plans differ »
Instead, Obama would use a windfall profits tax on oil companies to help low-income families pay their energy bills. He also insists he would put forth more effort than others to limit oil companies' influence in Washington.
Analysts and Obama said the proposal to suspend the tax temporarily would do little to stimulate the economy or lower gas prices and could leave roads in disrepair.
"It's a quick fix for people who believe cheap gas is their birthright," said Tom Kloza, chief oil analyst at the research firm Oil Price Information Service. "It's not a prudent thing to do."
Kloza said the amount of money motorists would save would do little to stimulate economic growth. The revenue from the gas tax is much needed for road repairs, he added.
"Look, somewhere down the road you have to use less," Kloza said. "As painful as it might be, higher prices do sway behavior toward a more energy disciplined America."
Obama is using the issue to liken Clinton to McCain, while she is trying to paint Obama as out of touch with working-class voters -- a group that will play a big role in the upcoming Indiana primary.
Indiana and North Carolina both hold their primaries next Tuesday.
Obama leads Clinton in the overall delegate count, 1,725 to 1,588. Clinton has a slight edge in superdelegates, leading Obama 256 to 234.
Since neither candidate can capture the 2,025 delegates needed to secure the nomination with wins in the remaining contests, the party's superdelegates probably will decide who gets the Democratic nod.
Superdelegates are party leaders and officials who vote at the August convention for the candidate of their choice.
North Carolina Gov. Mike Easley, a superdelegate, endorsed Clinton on Tuesday.
Recent polling suggests Obama holds a double-digit lead over the former first lady in that state, though no surveys have been released since Clinton's win in Pennsylvania last week.
After attending a rally with Easley in Raleigh, Clinton is scheduled to head to Indiana for events in Indianapolis, Hobart and Princeton.
Obama also is in North Carolina, where he has town hall-style meetings scheduled Tuesday in Winston-Salem and Hickory.
McCain continues his weeklong health care tour, with a speech Tuesday in Tampa, Florida.
McCain opposes federally mandated universal coverage. Clinton wants mandated health insurance coverage for all Americans, while Obama backs a plan that would mandate coverage for children but not adults. E-mail to a friend
CNN's Suzanne Malveaux and Jessica Yellin and CNNMoney.com's Steve Hargreaves contributed to this report.
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