By DAMIEN CAVE

THE YOUNG VOTERS who propelled Senator Barack Obama to victory in the United States presidential election may forever be known as Generation O. They were the force behind the campaign’s wide reach, opening hundreds of Obama offices in remote areas, registering voters and persuading older relatives to take a chance on the man with the middle name Hussein.
More 18- to 29-year-olds went to the polls this year than in any election since 1972 - between 21.6 million and 23.9 million, up from about 19.4 million in 2004, according to preliminary estimates from the Center for Information and Research of Civic Learning and Engagement. And 66 percent voted for Mr. Obama, according to exit polls by Edison/Mitofsky.
Many of them saw in Mr. Obama, 47, the values that sociologists and cultural critics ascribe to them. Government under Mr. Obama, they believe, would value disclosure and transparency . Teamwork would be in fashion, along with a strict meritocracy.
With two wars and a financial crisis to face, this generation may soon discover the limits of their consensus-oriented focus and unyielding faith in networks and communication. And with Mr. Obama’s focus on mobilizing younger supporters through the Internet, he may be alienating older Americans.
Throughout his campaign, Mr. Obama created an image of openness with his supporters through a steady stream of e-mail messages and Facebook postings. His supporters know, of course, that the text messages from “Barack” are the work of a campaign aide .
“You get the feeling that you’re becoming friends with him in that casual way,” said Reid Johnson, 31, a volunteer at the Obama office in Wilson, North Carolina. “I think everyone takes ownership of it because you feel like you know who he is.”
Only a hip-hop-loving, pickup-basketball- playing, biracial president-elect would send supporters an e-mail message on election night that said: “I’m about to head to Grant Park to talk to everyone gathered there, but I wanted to write to you first.”
He signed it simply “Barack.” After all, they were close. He and his biggest fans, the generation of young adults who voted for him in record numbers, together had slogged through 21 months of campaigning. And in his moment of victory, Mr. Obama shared the glow of success. “All of this happened because of you,” the e-mail message said. “We just made history.”
With that simple “we” in millions of inboxes, the post-baby-boomer era seems to have begun. The endless “us versus them” battles of the ‘60s, over Vietnam, abortion, race and gender, at least for a moment on election night, seemed as out-of-touch as a rotary phone.
And yet, Mr. Obama’s sweeping success could also breed trouble. “The risk is they vote for the first time, and then there’s this incredible long-shot win - ‘Gee, this is easy,’ ” said Kurt Andersen, a writer and former editor of New York Magazine.
Inevitably, he said, “growing up is all about disappointment and things not going well - so that is a natural next step.”
Ronald Alsop, author of “The Trophy Kids Grow Up: How the Millennial Generation Is Shaking Up the Workplace,” said that because today’s young Americans were trained to trust teams and systems - they love checklists - they often struggle when things do not go according to plan.
Compounding the problem, they have also been told all of their lives that they are destined for greatness. They have seen 25-year-olds become millionaires overnight with companies like Google, and after helping Mr. Obama win, the question is whether they will settle for less than a central role.
“They are used to getting a lot of awards and coddling from their parents, coaches and teachers,” Mr. Alsop said. “So if they’re put in some menial position, in a political or corporate environment, they are not going to be happy.”
On Mr. Obama’s Facebook page, there are already supporters like Viki, who wrote, “Please keep this dialogue going. We are here for you, and I am anxious to see, now that you have won, if you will keep your momentum with the people or let us go.”
As if on cue, President-elect Obama introduced a new Web site, change.gov, on November 6. “Share your story and your ideas,” it says, “and be part of bringing positive lasting change to this country.”
The site is in many ways an extension of the Obama campaign: casual, cool, interactive.
But if these are the traits of the young, might they alienate older Americans?
Many baby boomers are unlikely to be comfortable with this generation’s technological savvy and ease with blurred identities and mixed ethnicities. Peter Wolson, a former dean of the Los Angeles Institute and Society for Psychoanalytic Studies, said the 1960s helped give baby boomers a deep suspicion of “the other.” Their world was bifurcated: pro-war versus antiwar; communist versus capitalist.
“There is a fear of intimacy and merging because of the sense that you’ll be taken over by the other,” Mr. Wolson said.
Seeing a new crop of young people texting their way to the Oval Office may never soothe those fearful boomers. For others, the generational transition may bring relief as the country seems to move past old, entrenched conflicts.
Chuck D., 48, the rapper and former leader of Public Enemy, said he was amazed at the ease with which his 20-year-old daughter and her friends interacted with politics this year. While he spent his youth shouting the message “Fight the power” - releasing a song with that title in 1989 - his daughter fell in love with a candidate, voted for the first time and got exactly what she wanted.
He couldn’t be more pleased. “She doesn’t bring the burden of history with her,” he said. “ She’s free to make a healthy decision for the future.”