Before his arrival, the 200 or so people at the Missouri delegation breakfast were busy scanning the paper, forking their buttered eggs, struggling to stay awake as county officials talked about the day to come (scavenger hunt, chance of rain). Agenda items included the state's AAA bond rating and changes in farm policy. Then just as she's finishing up details of this afternoon's library tour, state Rep. May Scheve announces a "surprise guest."

Suddenly, it's like Daredevil landed in Jefferson City, all 6-foot-4, square-jawed, squinty-eyed marvel of him. Ladies faint, villains scatter.

Well, not really. This is an older crowd from the Show Me state. But still their faces light up, they fumble for cameras. Kitchen staff desert their stations. Women appear from every corner, pulling out something, anything, for him to sign -- ID tags, napkins, a white shirt cuff. "It's for my daughter!" "It's for my mom!" "I love your movies!"

Up on the podium, Ben Affleck says nothing much different than some of the county officials said earlier -- "Your state is critical . . . As goes Missouri, so goes the U.S. . . . The Republican Party has succeeded in confusing people."

But an air of glamour has coated this humdrum breakfast, and now everyone's glowing, Affleck included.

"It's exciting," he says afterward, ducking into an elevator barely big enough to contain him. "In some ways I'm better at this than acting. I mean, not that I think I'm bad at acting, but I love this."

These days large political gatherings call for a house celebrity, and at the Democratic National Convention this week that's Ben Affleck. There he is at the Yankees-Red Sox game waving with Kerry, speaking at a policy briefing with Bill Clinton and James Carville, pontificating with Bill Schneider and Al Sharpton on "Larry King Live," appearing on lists for more parties than he could possibly go to.

It's all sort of confusing -- isn't Affleck that action flick hero, known most recently for that spectacular flameout of an engagement to J.Lo? Actor Danny Glover and comedian Janeane Garofalo, who are also here, make sense as political activists. But Affleck?

Yet somehow, in the spectacle that is the convention, with its music and strobe lights and rock concert trappings, Affleck fits right in, another act in the prime-time variety show.

John F. Kennedy had his Rat Pack and John Kerry is starting to pick up his own celebrity entourage, mostly Hollywood lefty types enraged with Bush. He's had two big celebrity fundraisers in New York, dozens of smaller ones in Los Angeles. For a man who doesn't exactly scream life-of-the-party, it could be a good thing:

"It adds some glamour to him, lightens his image up," says presidential historian Robert Dallek. "If people think Kerry's a dour, cerebral guy, they may think maybe he is a fun guy if he's hanging out with celebrities, throwing his arm around them, standing shoulder to shoulder with them."

But these associations could have their downsides. Remember Rob Lowe, who videotaped himself having sex with a minor during the 1988 Democratic convention? More recently the Bush campaign seized on a vulgar joke by Whoopi Goldberg during one of the New York fundraising events to show Kerry is out of touch with mainstream American values.

"Increasingly Democrats are being labeled as the party of the Upper West Side and Malibu," says Eric Dezenhall, a Washington media consultant. "If people in the heartland are watching, that celebrity pandering may not play so well."

But Affleck is determined to be a loyal soldier. "This is a once-in-a-lifetime experience," he says after praising Kerry's courage and passion. "I told the Kerry campaign to use me in whatever capacity they want. And if they let me know I'm damaging, I'll get out of the way."

So loyal is he that on Sunday night when Kerry showed up at the Red Sox game, Affleck gave up his seat -- "He trumped me!"

So you have to wonder, who's pandering to whom here, and why would he bother?

When Washington and Hollywood mix, celebrity operates in unpredictable ways. Just before the main speeches began Monday night, Dennis Kucinich and Barney Frank walked through the halls unnoticed. The crowd waited patiently for Glenn Close to finish so Bill Clinton could come on. Up on the top floor, Al Sharpton wandered into one of the VIP skyboxes only to be told he had to leave, they're clearing the inside room for Affleck. Ken Burns watched the exchange from the outside booth, where he was trapped. Then in walked Affleck, with a small entourage that included his mother.

Affleck is at the top of the VIP heap, and, like so many Hollywood stars who've reached this apex, he is, at 31, undergoing something like a midlife crisis. He explains it by using the British concept of tallest poppy: "For two or three years as you grow and get famous you can't do anything wrong," he says. "Then they mow you over." "They" being the tabloids, newspapers, the culture at large.

Affleck became really famous at 25 when he and childhood buddy Matt Damon, both from Cambridge, Mass., wrote and starred in "Good Will Hunting," and then won an Oscar for the screenplay. They were a Horatio Alger story, two boyhood friends from working-class families who won the jackpot.

Since then Affleck has veered from indie films to romantic comedy to action flicks with no particular critical acclaim in any of them. His relationship with Jennifer Lopez turned him into a figure of lurid tabloid fun, his every expensive love bauble lovingly photographed. One movie they made together, "Gigli," is verging on cult status for its badness.

The union of Bennifer, as it was known, ended shortly after the tabloids published reports that Affleck had a lap dance at a strip club, a story he insists is "a 100 percent fictitious lie, and they know it." Even so, the experience singed him.

"I couldn't connect those images with my own sense of self," he says. "I became depressed about the Faustian nature of my life, that I've chosen a life where I'm exposed to criticism and invasiveness, that I've made the legal segue from private to public so people can write anything about me. I craved a segue into a different kind of life. Something I can get excited about. Something I think is more worthwhile."

Coming at politics this way, Affleck lacks the conspiracy notions many Hollywood types have about Washington. If anything, his take is less Oliver Stone than Mr. Smith on his first day.

Movies, he says, are part of the "superficial Chinese food culture. After half a year, there's no end result beside making a movie, and maybe some self-congratulation, or an award," he says. "It's not as important as giving people affordable health care, a great education, responding to something basic and fundamental in human society.

"Making movies is just making movies. If the world came to an end who would give a [expletive]?"

Affleck talks fast. He has grand unified theories and loves to spin them out. He's fond of phrases like "Jeffersonian model of dialogue." In between monologues he stops to tell a joke. Ooh, there's Al Gore down on the floor, so Affleck does his wicked Gore imitation. ("I wish he'd been president so I could have gone on 'Saturday Night Live' with this.") Ooh, here comes the dancing. "Delegates dancing. Not good."

Affleck doesn't speak in lefty cliches. He sounds like a party man, if not exactly original, then as cogent as the average House member: "The deficit is financing tax cuts for millionaires like me." He doesn't have the usual Hollywood causes -- Tibet, acid rain, world peace -- and instead subscribes to the party platform, with the exception of gun control.

Affleck is well aware that people make fun of celebrities who get involved in politics. He holds several theories about that: that most Americans learn their politics from entertainers anyway, meaning people like Rush Limbaugh and Jon Stewart, that celebrities at least don't ask for anything back, like tax breaks or less regulation, and that they risk a lot.

"People will say I don't want to watch that movie by Martin Sheen or Sean Penn. He supports Kerry," Affleck says. "And there's no group of people more career-obsessed than in Hollywood. Except maybe in Washington."

Affleck is dividing his time at the convention between fun events and what he considers annoying celebrity events. The former could include a delegate breakfast with a small, grateful crowd or the briefing with Clinton. The latter means the fundraising events where Affleck is wheeled out for throngs of starry-eyed donors, such as the DNC pool and bowling party Tuesday afternoon.

Affleck starts out in a darkened pool room where he meets a handful of people, Democratic National Committee Chairman Terry McAuliffe's children, Wesley Clark's wife, some staff. Then out to the harsh light of the bowling alley where a mob of more than 1,000 is waiting. Affleck delivers a gracious introduction of Gen. Clark, but no one seems to listen. They snap pictures of Affleck with their cell phones, send them to friends, press closer.

Affleck steps down, shakes a few hands but then quickly makes his way out. He leaves behind women giddy at having seen him, and Clark talking about "securing America's future" as the crowd moves like a wave down the stairs after the star.

Reporters have been asking Affleck whether he'll run for office. After all, he's wearing a suit instead of his usual T-shirt and baseball cap. Plus, he's a natural. He shakes hands, singles out little kids, speaks Spanish, writes his own speeches and adapts them to the audience: more about the military for South Carolina, more discussion of jobs for Missouri.

By a Tuesday news conference he's mastered the lingo so well that reporters have started asking him questions about outsourcing to India. If Affleck makes Kerry cool, Kerry has succeeded in making Affleck more serious.

But as the day drags on, the routine begins to wear. Can he talk to some delegates? How about another DNC thing tomorrow? Just half an hour? "This is a lot of politics for me," he says.

He doesn't admire Arnold Schwarzenegger but thinks about him a lot: a guy who was womanizing and running his mouth for years and then boom! He was governor.

But ultimately Affleck might be too lazy. Yesterday afternoon, during his exercise time, he takes a nap instead. Schwarzenegger would never have done that. "You got to think, would you rather be sitting by the pool, or going to some Elks lodge to eat some doughnuts and shake hands?" he says.

For the moment he settles on a Washington-style evasion: "I'd look into it, maybe sometime in the future."

Ben Affleck dazzled Missouri delegates at a breakfast session, where he was introduced as a surprise guest by state Rep. May Scheve.On his way to another delegate meeting, the actor stops to chat with former presidential candidate Wesley Clark. Affleck stands outside the kitchen door of a hotel meeting room, waiting for his next convention introduction.In Boston, Ben Affleck has been booked for parties and panels galore, such as the Comcast Power of 1 event with Amber Tamblyn and Danny Glover. Left, Affleck poses for pictures with fans.