( dpa ) - The four remaining Republican candidates for president debated Wednesday in the Ronald Reagan library in southern California, striving to show off their conservative credentials in the shadow of their party's celebrated hero.
Missing from the debate was former New York Mayor Rudolph Giuliani, who announced his withdrawal from the race earlier Wednesday following his disappointing performance a day earlier in the Florida primary.
The debate marked the last time the candidates will spar in public before next week's critical Super Tuesday contests, in which voters in more than 20 states will make their choices for the presidential nominations of both major parties.
According to reports after the debate, California Governor Arnold Schwarzenegger is set to endorse US Senator John McCain.
The most contentious moment in the debate came when former Massachusetts governor Mitt Romney sparred with McCain over whether Romney had ever advocated a timetable for withdrawal from Iraq. McCain and a majority of Republicans oppose any talk of withdrawal.
"I have never, ever supported a specific timetable" for withdrawing troops, Romney said, accusing McCain of using "dirty tricks that I think Ronald Reagan would have found reprehensible."
"It's simply wrong, and the senator knows it," Romney said. "I will not pull our troops out until we have brought success in Iraq."
McCain, who accused Romney of following a Democratic line on Iraq, said, "I unequivocally put my career on the line and said we had to support the surge."
Also taking part in the debate were Congressman Ron Paul and former Arkansas governor Mike Huckabee, both of whom complained that the CNN-sponsored debate's moderator was focusing on the two leading candidates at their expense.
"The dollar's crashing, and you talk about these technicalities about who said what when in Iraq," said Paul, the lone Republican presidential hopeful who has opposed the war. "How many men are you willing to let die for this?"
Huckabee chimed in: "If you want to talk conservative credentials, let me get in on that. This isn't a two-man race."
Another key issue was combatting illegal immigration, with Romney blasting McCain's moderate stance, which would have allowed many of the estimated 12 million undocumented immigrants to legalize their status in the US.