John McCain and Mitt Romney carried their bitter Florida clash into California on Wednesday, each impugning the other's honesty in a hot-tempered debate as they sought to attract voters casting ballots in five days in a coast-to-coast array of primaries and caucuses.

McCain, caustic for much of the debate, castigated Romney for what he said was a past insinuation that America should withdraw from Iraq. McCain contrasted that with his own early support for the "surge" of American troops that has reduced violence in some areas of the country.

Romney called the accusation "reprehensible" and said the Arizona senator was deliberately misrepresenting his comments because of a weakness for "Washington-style" negative campaigning. The arguments came in a 90-minute debate sponsored by The Times, CNN and Politico; a Democratic debate will be held in Los Angeles tonight.

Wednesday's gathering may have been held at the Ronald Reagan Presidential Library near Simi Valley, but the former president's famous adage that the GOP's "11th Commandment" precluded damaging fellow Republicans appeared lost to history.

The testiest exchange stemmed from an ABC News interview last April in which Romney, when asked, said that it was appropriate for President Bush and Iraqi leaders to devise "timetables and milestones" to measure progress in Iraq. In the closing days before Florida's Tuesday primary, McCain wielded the comments as evidence that Romney was ready to abandon Iraq.

The full quote included Romney's statement that such markers should be private so they would not signal American intentions to the enemy. Nevertheless, McCain insisted Wednesday that "timetables" were code for retreat.

In reply, Romney said, "Let me make it absolutely clear again tonight: I will not pull our troops out until we have brought success in Iraq." He added that "raising it a few days before the Florida primary, when there was very little time for me to correct the record . . . sort of falls into the kind of dirty tricks that I think Ronald Reagan would have found to be reprehensible."

"Governor, the right answer to that question was 'no,'" McCain countered, referring to the ABC interview. " . . . 'Timetables' was the buzzword for withdrawal."

McCain attempted to link Romney's comments on timetables to his unrelated refusal, before his presidential campaign began, to state a position on the troop surge.

"It's simply wrong," Romney said. "And the senator knows it."

McCain then threw back at Romney one of the sources of the animosity between the two: the millions of dollars in attack ads that the former Massachusetts governor ran against Mike Huckabee in Iowa and McCain in New Hampshire.

"Your negative ads, my friend, are -- have set the tone, unfortunately, in this campaign," McCain said.

Each declared the other unfit to assume the presidency.

"I know how to lead," McCain said at one point, sharpening a distinction between himself and Romney, a longtime businessman who never served in the military. "I led the largest squadron in the United States Navy, and I did it out of patriotism, not for profit. . . . I don't need any on-the-job training."

The former governor, after praising McCain's military service, declared that voters "don't look to senators" for leadership. Senators, he said, are "committee chairs, and they call that leadership."

Later, when each was asked why Reagan would have endorsed him, Romney said he -- and not McCain -- was part of the party's "heart and soul."

"Ronald Reagan would not approve of someone who changes their positions depending on what the year is," McCain replied.

The tension between McCain and Romney, the two leading Republican candidates, was heightened because the two sat next to each other, uncomfortable and occasionally glaring, as the insults burst forth. Former Arkansas Gov. Huckabee and Rep. Ron Paul of Texas, the two other participants, were often left out.

"I didn't come here to umpire a ballgame between these two," an irritated Huckabee said at one point, motioning to McCain and Romney. "I came here to get a chance to swing at a few myself."