Before Rudy Giuliani walked into a luncheon in his honor on Monday, the strings were playing "Someday My Prince Will Come."

A prince? It's been like that for the past two days. He is trying not to hog attention, but when the former mayor slipped into Madison Square Garden earlier in the day to hear the current mayor address the Republican National Convention, a media throng ran to catch him on camera. The whole scene threatened to embarrass Michael Bloomberg, and so Giuliani granted an impromptu news conference, right there, just to neutralize the press.

He pops up everywhere: on Ellis Island, with Vice President Cheney; onstage before the musical "42nd Street," giving a quick pep talk; rallying Jewish voters on a yacht off Chelsea Piers, before finally addressing the delegates as Monday night's cleanup hitter.

He talked about leadership in the strongest terms. "There are many qualities that make a great leader, but having strong beliefs, being able to stick with them through popular and unpopular times, is the most important characteristic of a great leader," he said. And then he defended the president and brought the delegates to their feet:

"And since September 11, President Bush has remained rock solid. It doesn't matter to him how he is demonized, how the media ridicule him or misinterpret him or defeat him. They ridiculed Winston Churchill. They belittled Ronald Reagan. But like President Bush, they were optimists. Leaders need to be optimists. Their vision is beyond the present, and it's set on a future of real peace and security. Some call it stubbornness. I call it principled leadership."

But while the leader of the nation has polarized it further, Giuliani remains frozen in time, transformed by Sept. 11, an icon of that day, and one of the few still untarnished. He, more than any other political figure, evokes this shattered city of three years ago just by showing up. He has not spent any of his capital (although he's certainly made a lot of it, as a consultant). "Rudy left the stage while people were still applauding," said Sen. Lindsey Graham (R-S.C.).

Before 9/11, Giuliani was not a widely liked or admired figure -- he was the combative, cranky mayor who had busted crime and cleaned up Times Square but had publicly humiliated his wife, who remained in Gracie Mansion with their children while he squired his "friend" Judith Nathan around town. He was squatting in an apartment with friends -- two gay men -- in some kind of sitcom that had not yet become a pilot. (Watch all hell break loose when the mayor returns to find that someone has polished off his bottle of Amarone! Watch them fight over who gets to hold the remote!) He seemed to need to fight with everyone, scaring aides and rival pols half to death. Anyone with the noun "advocate" before his or her name felt his fire -- unions, public advocate Mark Green, lefty mayoral candidate Ruth Messinger, even the homeless and labor activists whom he kicked off the steps of City Hall. By the end of his second term, he resembled a walking headache.

Then the jets hit the twin towers, and Giuliani displayed a full range of leadership qualities -- grace under pressure, extraordinary stamina, steeliness, physical courage. He himself nearly died that day in the command center set up near the World Trade Center. Bush's iconic moments have descended into parody: standing on the carrier, Mission Accomplished. Even the bullhorn at the smoking ruins of Ground Zero is today undercut by arguments over underfunding of homeland security for this city of 8 million. The difference: Nothing about Giuliani in the days after 9/11 looked staged. For better and for worse, Giuliani could never be "managed." His bravery and coolness under fire were as authentic as his crankiness, and Sept. 11 forced those qualities forward.

Monday night, Guiliani evoked the sorrow of that terrible day, then said that Americans essentially owe it to those who died to vote for Bush. "George Bush stood near the fallen towers, and he said to the barbarians . . . they will hear from us. Well, they heard from us," he said, in Afghanistan, in Iraq and in Libya, where the dictator pledged to dismantle his weapons of mass destruction. ". . . So long as George W. Bush is our president, is there any doubt they will continue to hear from us? . . . We owe that much and more to the loved ones and heroes that we lost on September 11."

At 60, he now heads Giuliani Partners, a consulting firm that offers security strategies to businesses. These past few days, he has been charming in his rough, up-from-working-class, uncharming way. He's got that new wife, who smiles at his side like she's still delighted to be there, rather than ready to go home and kick off her shoes. He's got that new hairdo, giving up on the comb-over to just let it go bald. He loves to play golf with his son, who is a senior in high school. When Tim Russert, on Sunday's "Meet the Press," called him the "darling of the Republican Party," Giuliani laughed and corrected him: "Rudy from Brooklyn is not a darling. I came to terms with that a long time ago."

Russert reminded him that the head of the gay Log Cabin Republicans has said, "You can't craft a vicious, mean-spirited platform, then try to put lipstick on the pig by putting Rudy Giuliani and Arnold Schwarzenegger on in prime time." And Rudy cracked, "Which am I, the pig or the lipstick?"

In an especially sly trick, he actually has been championing the Republicans as a party of diversity, just because convention planners have given him -- this social moderate, this signer of gay-union legislation, this defender of abortion rights, this wearer of drag (once on "Saturday Night Live") -- a prime-time speaking role.

"We're a party which appreciates difference," the former mayor said earlier Monday. "The Democrats had a convention in which everybody was saying the same thing," as if that were a politically bad and boring strategy.

He has been offering kind words to his successor, reminding grumbling New Yorkers that the Republican invasion and widespread television coverage is good for the city. And he has been swatting away questions about his higher political aspirations with sports analogies.

"I'm not thinking of 2008," he told reporters demanding he share any presidential fantasies. "We don't look beyond the current game. That's how you don't get into the Super Bowl."

But Graham, a conservative Southerner, said he wants Giuliani back in the game. "I think he's a great asset to our party," said the senator, who had played golf with Giuliani twice last week and declared he had passed "the golf character test."

"People like him. We're lucky to have a leader of his stature. The only way we are going to survive as a party is to appeal to a wider group," including the social moderates, Graham said. "Ten years from now if we don't, we're gonna be a dinosaur party."

As if mindful of the need to build a new constituency and shape the news, Giuliani stopped briefly, before sitting down at the luncheon honoring him, to entertain a question from a 13-year-old reporting for a children's news Web site. Natasha Kirtchuk got the classic Giuliani treatment. "We were asking him what he thought could be done about the millions of children without health insurance," Kirtchuk said later, "but we didn't get to finish our question. He just started talking, and then he told us what would be a good story to write."

Kirtchuk lives in Brooklyn, and she remembers all too well the day the towers fell. Asked what she thought of her former mayor's performance in the aftermath of 9/11, she paused. "As a reporter, I'm not really allowed to say," she began. "But, as a resident, yes, I think he did a good job."

Larger than life: Former New York mayor Rudy Giuliani at the luncheon in his honor at Cipriano's.Rudy Giuliani, with wife Judith Nathan, at yesterday's luncheon in his honor.