Rudy Giuliani hides his rage behind ridicule.

It's not often that presidential candidates publicly share the contents of their dreams. But, on a chilly late November afternoon, Rudy Giuliani was standing beside an outdoor patio fireplace in Windham, New Hampshire, doing just that. The occasion was a campaign appearance at a supporter's suburban home. Although it was Sunday afternoon, Giuliani was all business in a wrinkle-free dark pinstriped suit, bold red tie, and shiny black loafers. As the fire crackled away behind him, Giuliani embarked on a strange tangent, hailing the conservative French president, Nicolas Sarkozy, for trying to cut taxes, expand school choice, and generally make socialist France more like capitalist America.In his dream--which Giuliani claims he's had at least five times--he sees Sarkozy flying in a jet from France to the United States. As the Frenchman soars over the Atlantic, another jet approaches from the opposite direction. The two planes pass so close they nearly collide, and Sarkozy sees three passengers in the other plane. "Sarkozy waves to the three people, and they wave back," Giuliani explained merrily. "It's Hillary Clinton, Barack Obama, and John Edwards. They're going to France to see if they can get all those failed French policies, take them over here, and put a lid on our growth." Big laughs from the crowd. Sometimes a fuselage is just a fuselage, but, in this case, it was the vehicle for a crudely demagogic attack on Democrats as un-American. Yet Giuliani delivered the story with a bemused smile and a New York twinkle in his eye, almost like Sinatra ribbing Dean Martin at a cabaret. And that, in a nutshell, is the sort of presidential candidate Giuliani has been: all charmer and no snake. He delivers his political shots like a comedian dispensing one- liners. His chief weapon isn't vitriol; it's ridicule. It's not what you'd expect from the rude, combative, and sometimes vindictive mayor of New York, about whom a book was written titled Nasty Man. Nor is it what you'd expect from a candidate known for his grim-faced post- September 11 "toughness." But Giuliani clearly knows his temperament is a potential liability. Hillary Clinton made an issue of it during their abortive 2000 Senate showdown. And, after Giuliani and Mitt Romney traded punches on crime and taxes this past week, Romney's spokesman--in obviously calculated language--declared that "the mayor's nasty side" was becoming apparent. Which is why to follow Giuliani on the trail is to see his determination to show off the sunnier side of Rudy. At a town hall meeting in a Nashua hotel ballroom recently, Giuliani boiled down his candidacy to a fundamental idea: being on offense--offense against terrorists, and in growing the economy. But Giuliani is on offense in his campaign as well. This strategy primarily targets Democrats, the press, peaceniks, and assorted liberal clowns; above all, it targets that reliable punchline, Hillary Clinton. When a questioner in Laconia, New Hampshire, asked about driver's licenses for illegal immigrants, Giuliani delivered a comic monologue with Broadway flair. "You know that whole thing where Hillary was first--oh, I'm gonna get all confused," he replied, feigning bewilderment. "I don't remember if she was first for illegal immigrants having driver's licenses, then she was against it. Then she was for it and against it. Then she was for it and against it in the same sentence ..." And on it went. It was like a "who's on first?" routine, to the clear delight of his audience. Giuliani has shown this cheeky streak before. Preparing for his 2000 Senate run against Clinton, he visited Arkansas (allegedly on a fund-raising swing) and arranged a photo-op on the steps of the governor's mansion in Little Rock, which the press dutifully noted was the "former home" of the carpetbagging Clinton. Giuliani denied that he was tweaking Clinton. "It's not in my personality to do anything like that," he said--but The New York Times added that he "suppressed a smile" as he spoke. Back in New York, Giuliani rubbed it in by flying the Arkansas state flag over City Hall to "thank" his GOP hosts there. But Giuliani wasn't always so insouciant. He was known as a disciplinarian quick to call his rivals "jerks" and "morons." He once suggested to the mother of a teenaged robbery suspect shot by cops that her parenting skills may have been to blame, and he unleashed a famously elaborate radio tirade against a zealous ferret lover who called in complaining about a city ban on the animals. ("There's something deranged about you!") In 1998, a New York Times columnist described him as "snarling, bullying [and] hot-tempered." Seeing an opening in the run-up to their would-be showdown, Clinton began to cast Giuliani as a loose cannon too temperamental for the Senate. "I can't be responding every time the mayor gets angry," Clinton chuckled at one December 1999 news conference, "because that's all I would do." The Clintonites have already hinted that, in a 2008 matchup, they would try to paint Giuliani as mean and angry again. But Giuliani seems determined to foil them. In a Greenville, South Carolina, ice cream shop last month, he pulled from his pocket a piece of paper on which he said he'd been keeping track of Clinton's new spending proposals, drawing instant laughs from the crowd. Last month, he spoofed liberals who want to ban the use of torture: "They talk about sleep deprivation," Giuliani told an Iowa audience. "On that theory, I'm getting tortured running for president of the United States." In New Hampshire last weekend, he lumped in critics of the war on terrorism with 1960s hippie peace activists. "You don't achieve peace by singing songs about peace and holding hands," he cracked. In Laconia, Giuliani somehow steered a question about knitting-machine jobs shipped overseas into a riff on the evils of universal health care, and then a reference to the Michael Moore film Sicko: "Appropriate name for a Michael Moore movie," Giuliani cracked, to another round of approving chuckles. For months, Giuliani has coasted above the campaign fray on the strength of his 9/11 celebrity. But, in New Hampshire this past weekend, things took a sharply rougher turn, as Giuliani and Romney bashed one another repeatedly over their respective governing records. The general election promises to be even more brutal, if recent history is a guide. Can Giuliani really suppress his inner bully? Already, one can glimpse flashes of a darker side, as when Giuliani accuses Democrats of "defeatism," "pessimism," and emulating "foreign principles." But more revealing, perhaps, are Giuliani's campaign aides, who can be downright savage. After Joe Biden called Giuliani unqualified to be president in one recent debate, Giuliani's communications director, Katie Levinson, lashed out with a startlingly vicious press release that taunted Biden as a plagiarist, said he'd "never run anything but his mouth," and asserted that Levinson herself has "a better chance of becoming president than [Biden] does." Similarly, after John McCain recently tweaked Giuliani for his friendship with the now-indicted Bernie Kerik, Levinson ripped "McCain's pure desperation in the face of a failing and flailing campaign." Most recently, Giuliani's campaign manager, Mike DuHaime, told reporters in New Hampshire last weekend that Mitt Romney had been "a mediocre one-term governor." For the time being, however, Giuliani looks remarkably unflappable. That was evident on a recent cold Saturday night, when a grinning Giuliani, in a black overcoat, marched purposefully down Main Street in Nashua, New Hampshire, as part of the town's annual holiday festival. Giuliani, the celebrity, moved at the center of an anarchic mob of reporters, cameramen, autograph-seekers, shrieking teenage girls, and bodyguards, all corralled by his team of stern young female press aides in stylish boots and designer winter coats. At one point, a drunken man with a cigar in his mouth broke through and draped his arm around Giuliani's shoulders. "Mayor Giuliani, how ya doin'?" he boomed. "What kind of cigar is that?" Giuliani asked cheerfully, just before the man was yanked away by his bodyguards. The old Rudy might have popped the guy. But the new one never broke stride. He just kept smiling.