BOCA RATON, Fla. (AP) With their rivals fading, John McCain and Mitt Romney maneuvered to be seen as the strongest Republican general election candidate.

Both backed away from President Bush and took on Hillary Rodham Clinton during a Thursday debate.

His campaign flagging, Rudy Giuliani tried to claw his way back into the leaders pack by taking on his two rivals over their positions on a national catastrophe insurance fund dear to Floridians.

Four days before Florida's high-stakes primary, polls show the race tight between McCain and Romney as Giuliani trails widely. The outcome of Tuesday's contest will give one candidate a leg up for the GOP nomination and set the stage for a virtual national primary Feb. 5.

No matter who wins the party nod, he will be saddled with the record of a president whose job approval rating is in the mid-30s as well as two wars and, perhaps, a recession all ammunition for Democrats hungry to regain the White House.

Thus, McCain and Romney offered passing praise for the current Oval Office occupant but mostly separated themselves from him. The two gave lukewarm support for his economic stimulus package.

"There's a great deal that is effective in his plan. I just wish it went further," said Romney, a venture capitalist and former one-term Massachusetts governor.

McCain, an Arizona senator who twice voted against Bush's tax cuts, said he would support the legislation but added: "I'm disappointed because I think it's very important that we make the Bush tax cuts permanent."

At the same time, each sought to show he was the most capable to go up against Clinton, who both clearly view as the most likely Democratic nominee. Each brought up the Democratic debate in South Carolina on Monday and Clinton's position on the war.

U.S. troops "don't want us to raise the white flag of surrender like Senator Clinton does," McCain said, adding that doing so would mean expenses "in American blood and treasure, because al-Qaida will then have won."

Added Romney: "Look, the success over there is due to the blood and the courage of our servicemen and women, and to General (David) Petraeus and to President Bush. Not to General Hillary Clinton."

Giuliani, too, tried to get into the act, arguing that Clinton once was for the war but now is against it. But he more than once found himself on defense, once over his dwindling poll numbers in Florida and at another point his personality.

The former New York mayor seized the spotlight when it was his turn to ask another candidate a question, the pairings chosen by draw. Giuliani raised the topic of national catastrophic insurance fund. He is alone among Republican candidates supporting it and is trying to use it to gain ground.

His question was supposed to go to Romney but Giuliani first turned his fire on McCain.

"Senator McCain has said that he does not support a national catastrophic fund as a backstop. I do," Giuliani said. "Senator McCain believes that FEMA should handle this."

"Who's answering this question?" McCain asked, laughing.

"Well, you can answer it too, John," Giuliani responded.

Turning back to Romney, the ex-mayor said: "I'm not sure exactly the position that you took on it. And you said you were going to talk to the insurance companies and get their advice."

Both Romney and McCain got to answer.

Overall, the debate lacked the biting tenor of previous gatherings.

The strongest tussling was mild.

Romney noted that McCain had voted against Bush's tax cuts but now wants to make them permanent. "He should have voted for them the first time around," Romney said.

Asked whether Romney raising some $250 million in fees in Massachusetts is equivalent to raising taxes, McCain said: "Well, I'm sure those people that had to pay it did, I would imagine."

At several points, the candidates lavished praised on and lobbed softballs at opponents whose Florida performance could take votes away from their chief antagonists. Romney needs Giuliani to siphon supporters from McCain, while McCain needs Huckabee to do the same from Romney.

So, Romney asked Giuliani how he would make sure that trade "levels the playing field" as the United States seeks to compete with China. And, McCain wanted Huckabee to explain how a national sales tax, a Huckabee pet proposal, wouldn't cause low-income people more pain than others.

Instead of sparring outright with one another, McCain and Romney gave Bush as well as Clinton and the Democrats the brunt of their criticism.

"Look, the president of the United States signed into law two years in a row pork-barrel-laden bills," McCain said. "I will, as president, veto every one of these big spending bills."

Romney was just as pointed, if not more so: "I'm not going to run on that record, I'll tell you that. I can run on my own record."

McCain argued that Democratic presidential candidates will increase taxes, spending and the size of government, adding: "There is nothing that the Democrats have said, that I have seen, except tax and tax, spend and spend, elect and elect."

A moderator asked Romney a question about Clinton and her husband, the former president, giving Romney an opening to press his argument that he was most able to defeat Clinton. He even brought her up as he answered a question about his Mormon faith, injecting: "I believe that I'll ultimately get the nomination and I believe in a head-to-head with Hillary Clinton."

Liz Sidoti covers the Republican presidential race for The Associated Press.