SIMI VALLEY, Calif. — There may have been four GOP contenders for the White House on stage Wednesday, but the debate before so-called "Super-Duper" Tuesday was really only between two of them — newly anointed front-runner John McCain and Mitt Romney.

The pair sparred several times during the 90-minute CNN debate at the Ronald Reagan Presidential Library here — especially over whether Romney had ever supported setting timetables for pulling out of Iraq — much to the frustration of the other Republicans still in the race, former Arkansas Gov. Mike Huckabee and Texas Rep. Ron Paul.

And although Romney's advisers said afterward they were pleased with his performance, much of their time in the post-debate "spin room" was spent deflecting questions about why the former Massachusetts governor has yet to buy television commercials in any of the 20-plus states, including Utah and California, that have voting Tuesday.

McCain, who seized the title of the man to beat in the race for the Republican nomination with his victory Tuesday in Florida's winner-take-all primary, was endorsed before the debate by longtime front-runner and former New York City Mayor Rudy Giuliani. McCain is expected to be endorsed today by California Gov. Arnold Schwarzenegger.

There was little new ground covered in the debate, but sparks flew between McCain and Romney over the Iraq question. Romney said he'd never supported setting a deadline and accused the Arizona senator of "Washington-style old politics, which is to lay a charge out there regardless of whether it's true or not" in the Florida race.

McCain countered by suggesting Romney was unwilling to put his reputation on the line by supporting the war during what he said was a critical time, when the newly elected Democratic majority in Congress was pushing for a pullout from Iraq.

And McCain went on, suggesting that Romney has spent millions of dollars of his own money on attack ads, against Huckabee in Iowa and McCain in New Hampshire. Romney lost Iowa to Huckabee and New Hampshire to McCain.

"Your attack ads, my friend, have unfortunately set the tone for this campaign," McCain said.

Paul, a one-time Libertarian candidate for president and an opponent of the war in Iraq, made it clear he was tired of listening to the bickering. "I find it rather silly, arguing the technicalities of a policy you both agree with," Paul said. "The dollar is crashing and you're talking about those technicalities of who said what, when."