GRAHAM, N.C. - Offering Americans a summer tax holiday from soaring gasoline prices as another example of why she is the best candidate for president, Sen. Hillary Clinton took aim on Monday at her Democratic Party rival Sen. Barack Obama.

“This is one of the big differences in this race. My opponent Senator Obama opposes giving consumers a break on the gas tax at the federal level. I support it. I understand the American people need some relief,” she told supporters gathered in a fire station here.

“Meanwhile Sen. (John) McCain says he’s all for a gas tax holiday, but he won’t pay for it. Well, that is a mistake because we can’t give up on building and repairing our roads. My plan is 100 percent paid for with the windfall profits tax on Big Oil,” she said.

U.S. drivers are reeling from soaring costs at the pump that have seen gasoline reach $4 a gallon in some parts of the country, with an average price around the country of $3.60, after oil scaled a record near $120 a barrel.

Clinton’s plan would use the windfall profits on oil to subsidize the federal gas tax holiday over the summer to make sure the country’s Highway Trust Fund — used to build and repair roads and bridges — doesn’t suffer.

Major oil companies report first quarter earnings this week and are expected to chalk up bumper profits thanks to record crude prices, with Exxon Mobil forecast to see net income rise around 22 percent to over $11 billion.

“Last year, Exxon Mobile made $40 billion in profits. So you paid through the roof and they made out like bandits. I don’t think those profits were the result of a free and fair market,” she said, blaming energy market manipulation.

Click here for more Reuters 2008 campaign coverage.

Photo credit: Reuters/Frank Polich (Clinton campaigns in Indiana).