In the media-saturated Hamptons, the summer's poolside reading is emblematic of life in the 21st century: the 9/11 commission report and Us magazine. There doesn't seem much alternative to the daily diet of terror and trivia -- except for the lingering impact of Barack Obama, which continues to reverberate as the only bounce worth talking about.

Obama-mania has reminded everyone that seriousness can be electric. The breakout keynote speech at the Democratic convention by the 42-year-old African American senatorial candidate from Illinois was one of those moments when the cultural momentum suddenly pauses. Could the world of ideas be exciting again? Star quality has become so debased it was almost spooky to see celebrity suddenly attached to the evoker of a political vision instead of the winner of a reality show or the star of an overhyped movie. Two days later when Obama emerged from the convention hall in Boston to climb into a modest white sedan he was mobbed like P. Diddy.

In seen-it-all New York, people are still a little unsettled by Obama, even as we go about our daily business of being terrified. We try to work up interest in formerly reliable dross, but even surefire stuff like the Lori Hacking murder case (aka Laci Peterson 2) doesn't quite energize the airwaves the way it did before Obama. It's as if the wiry young politico with the pianist's hands had landed from outer space, bringing a new message to Planet Media.

With that wildly exotic resume he was the perfect emissary from the future. About the only category that comes close to defining him is African American, but even before he hit the national stage he was gerrymandering the American mindset. In the Senate primary in Illinois he won the blue-collar communities around Chicago, communities that supposedly would never support a black candidate. And then there is his genderless air, reminiscent of Fred Astaire (who left sex to Ginger Rogers). He had the unexpected effect of making smiley John Edwards, the media darling before the convention, seem too class-bound and, well, paleo-American. If Obama is not from outer space he is someone who confounds stereotypes, frustrates attempts to pigeonhole him and yet shows the way to the future. As Charles Ogletree, his professor at Harvard Law School, told me, "Barack's not just a New Democrat, he's a new politician -- smart, street-savvy, able to make mistakes but recover -- who will not be pushed into a narrow ideological closet."As Obama campaigned yesterday in Urbana, Ill., young voters in standing-room-only crowds were transferring change from their pockets into his hand.

What remains haunting about the Obama moment is not just the birth of a political star. Or even of the thrill of hearing the man of no category talk about the need for America to reject the bitter politics of category. It was the fact that his charisma meant he was listened to rather than simply heard. His speech was a reminder of how great it is to hear a passionate new voice speaking at length about the things he believes, without cliches or gimmicks or smart-mouthed contemptuousness.

The media have gotten so damn postmodern. All they talk about when a speech is done is not the content but how it plays. Does it have legs? Will it fly? It's one of the strange ironies of the age of mass communication that people of ideas have to find every conceivable way not to talk about them in order to get attention. The poster boy for that has become poor Ben Affleck, who showed up in Boston in the John Kerry promotional entourage. Since a run of movie flops and his interlude as J. Lo's photo op accessory, Affleck suffers the indignity of selling more magazines when he isn't talking about his own life or work but is caught in the slipstream of somebody else's. Clueless "insiders" going on about his relationship with J. Lo or Jennifer Garner are considered more commercial than he is. No wonder he's trying to change the subject to universal health care.

Bill Clinton and Al Sharpton broke through, too, but they still carry baggage. Sharpton ran 10 minutes over his allotted time because he could. He was greedy for the limelight for what he does best -- blast his demagoguery from the pulpit -- without the usual burden of being the political clown.

Clinton chose a hotter tactic: actually staying within his allotted time. In Boston, he knew he was on, really on, and from the floor you could almost taste his joy when he got up there with an ecstatic little laugh and started playing the riffs he had honed on the book-tour circuit. For instance, there was the one where he wraps his metaphorical arms around President Bush and Vice President Cheney as fellow Vietnam dodgers and slyly pulls them under the water with him. Or the rogue-dog rap about being so well looked after by the Bush administration now that he's rich. He knew that up there no one could ask him about whether he regrets his affair with Monica Lewsinky and he was going to make the most of it. Maybe there could be a channel just for this -- remembering people at their best. Where you watch the young Michael Jackson dance and sing for hours or see Kobe in an endless basketball leap instead of stooped forward outside a courtroom surrounded by his posse of shame.

Obama hasn't had enough press yet to know what a pure luxury he enjoyed: the spotlight on what he stands for. He probably doesn't fully realize the dimensions of what he achieved. The media are addicted to the political equivalents of a Janet Jackson moment -- the Dean Scream, the Teresa "Shove it." Barack Obama did something historic. He broke through the noise with something positive.

(c)2004, Tina Brown

U.S. Senate candidate Barack Obama speaks at the Democratic Convention on July 27.