On his campaign bus, where he chats up reporters for hours on end, John McCain was asked the other day how his presidential candidacy is faring.

"We're going to take some setbacks, particularly with my proclivity to put my foot in my mouth fairly frequently," he replied. No one gave him an argument.

In an age when candidates offer carefully rehearsed sound bites in an effort to micromanage their message, the Arizona Republican is running for president by running his mouth. During his now-famous rolling press conferences, the senator rambles on about politics, the military, taxes, visiting Vietnam, his wife's ex-boyfriend and suggestions that he has a darker side. He blabs and banters and jokingly called an Associated Press reporter a "jerk."

"McCain is easier to get access to than a Hong Kong hooker," Time declared in this week's cover story on "The Real McCain," describing the "bold and risky adventure" of "a completely unguarded presidential candidate, just being himself."

For now, at least, it's working. In what has developed into a sweetly seductive relationship between the senator and the press, he smothers journalists with access and they produce colorful copy. McCain may not be "completely unguarded"--he ducks some questions--but he is endlessly available.

It is a tactic born of necessity. "We've got a good message and we don't have $60 million," says McCain adviser Mike Murphy. "We need the attention of the media." He contrasts the McCain talkathon with the more scripted appearances of George W. Bush, saying the Texas governor campaigns in "a titanium bubble."

Aides sometimes cringe at McCain's flights of candor, and with good reason. On one bus ride, McCain described a minor diplomatic flap as "one of the many reasons I hate the French." On another, recalling his days in a Hanoi prison camp, he referred to the Vietnamese as "gooks." Yet he rarely gets burned.

"At one level, the press protects him," says Jacob Weisberg, political writer for Slate magazine. "He delivers these stupid lines all the time. The typical response from journalists is either not to report it or to congratulate him for being so blunt instead of treating it as a gaffe. . . . If Bush had talked about 'gooks,' everyone would say how callow he is and how he's not up to running U.S. foreign policy."

Says ABC correspondent Linda Douglass, who interviewed McCain on the bus: "I have never seen a candidate allow himself to be videotaped at length like that, with no aides watching, listening, taking notes or telling you to cut. He's clearly winning us all over, and we have to be careful about that."

While most candidates talk up their chances, McCain engages in anti-spin, telling reporters that "this is not a two-person race" and that rival Steve Forbes shouldn't be counted out. At a New Hampshire dinner with two reporters, McCain described himself as "stupid" and "cocky" for having performed poorly at an earlier debate.

And it's hard to imagine another candidate taking Time's Jay Carney into his messy bedroom to show off the family's pet iguana. Or admitting to Carney: "Maybe I have peaked too soon."

"You get the sense you're being manipulated by candor, rather than manipulated by subterfuge and deception, but it is a strategy," says Carney. McCain is gambling "that you'll put whatever potentially damaging statements he makes within the context of an overall picture of the man. That contrasts pretty starkly with a lot of other candidates and politicians."

Reporters covering Bush and Vice President Gore grumble that on the rare occasions they are granted an interview, the candidates repeat chunks of their stump speech and never say anything revealing. Indeed, journalists spend huge amounts of time interviewing aides and advisers to reconstruct scenes that might shed light on the "real" candidate.

McCain, by contrast, spends so much time hanging with reporters that they run out of questions and start shooting the breeze--a neat feat for a conservative Republican charming the so-called liberal press.

McCain breaks the usual rules in public appearances as well. At a packed town hall meeting here at Phillips Exeter Academy, he was asked about his lowest moment in politics, his involvement in the Keating Five influence-peddling scandal.

Rather than minimize his role in the long-ago mess, McCain castigated himself. He said his efforts had "created the appearance of impropriety, which was indeed wrong. I was judged guilty of poor judgment. The fact is, it was the wrong thing to do, and it will be on my tombstone, and deservedly so."

At another point, the Arizonan took a whack at the state with the biggest batch of electoral votes, saying: "We hate California, they're always stealing our water." As for why he's running for president, McCain invoked the issue that his strategists would love to avoid.

"Well, my wife, Cindy, believes it's because I received several sharp blows to the head while I was in prison," he joked.

Reporters on the "Straight Talk Express" come away "sort of flabbergasted," as Fox's David Shuster put it. "Everything he does, everything he says, every little joke could end up in a story."

But there is a method to the seeming madness. "In seeming to be so open, honest, candid and unscripted, he defuses all the frustration that builds up when you can't get to the candidate," says ABC's Douglass. "He kind of has the ability to make the reporter his friend."

One area in which McCain doggedly stays "on message" is his refusal to criticize front-runner Bush, despite constant invitations from reporters to do so. He told the gang on the bus that while he might differ with Bush on an issue, "it doesn't mean I have to say, 'You're wrong, Governor, you're deceiving people, blah blah blah.' "

McCain seems to enjoy all the schmoozing, but he also knows that the Fourth Estate is a constituency to be courted. "Whatever I consider to be a success is meaningless," he says. "It's what the media consider to be a success."