WASHINGTON — The presidential election will hinge in large part on the Election Day turnout of younger voters, who surveys show favor Senator Obama by a large margin but also rarely show up to vote in the same percentages as the older Americans who favor Senator McCain.

The Obama campaign has established a network of “youth directors” as part of its field operations. The aim is to register and get to the polls the youth vote, which Democrats have been trying to attract for nearly 40 years.

The Democratic party has in the past focused its registration efforts on high-profile celebrity endorsements. In 2004, documentary filmmaker Michael Moore promised to purchase underwear for students if they voted, and rap impresario Sean “Puffy” Combs spearheaded Vote or Die, a campaign to turn out young voters.

This year, both presidential campaigns are competing for young voters through social networking Web sites and the kinds of retail politics that have been a facet of American politics since the nation’s founding.

While voters between the ages of 18 and 24 do not go to the polls in the same numbers as senior citizens, there is some evidence to suggest this may be changing. In 2004, for example, 40% of this cohort turned out and the majority of them voted for Senator Kerry. That was the highest youth turnout since the 1972 election that pitted Senator McGovern against President Nixon.

The director of American University’s Center for the Study of the American Electorate, Curtis Gans, said the high turnout among young voters was due to “the polarization created by Bush. They were voting in the negative.” He added: “They have been and they will still be highly supportive of Obama. We don’t have a new millennial generation as some have claimed, but there is no question young people are mobilized by Obama, who is a different and transcendent personality. There is no reason to believe they will not show up in the general.”

The latest poll from the Gallup organization, conducted between September 1 and September 7, shows young people favoring Mr. Obama at a rate of 60%, versus Mr. McCain’s 32% .

The editor in chief of the Gallup Poll, Frank Newport, said Mr. Kerry’s campaign harangued his outfit in 2004 for missing what they predicted as a huge turnout surge for the youth vote.

“This year a lot of people say the same thing about Obama,” Mr. Newport said. “We know Barack Obama’s campaign will be registering 18-to-29s. We don’t know the extent to which 18-to-29s will turn out at a higher percent than they have in prior elections.”

The youth vote director for the Obama campaign, Leigh Arsenault, said she was optimistic about youth turnout in November. “I think right now, young people are engaged in this election,” she said. “For example, in Iowa, youth turnout was up 103% from 2004 in the primary. We won the Iowa caucus by an estimated 20,000 votes, and the margin among young people was 17,000. Young people turned out at the same rate as older voters.”

To make sure young people turn out for the election, Ms. Arsenault oversees 700 chapters of Youth for Obama. She said the campaign is making sure that college campuses are manned with volunteers who set up tables with voter registration materials. “In Florida, they have used ironing boards to register voters. Small, innovative ideas like that can help attract new voters and build buzz for this election,” she said.

The effort is not limited to ironing boards. The Obama campaign has also set up a Web site, VoteForChange.com, that also provides voter registration information to potential voters. The campaign is also trying to recruit new voters through social networking Web sites such as MySpace.com and Facebook.com. Finally, the campaign is working to get surrogates such as the pop music singer Tatyana Ali to speak at colleges on behalf of Mr. Obama.

The political director of Young Democrats of America, Tony Cani, said the key to getting young people to vote is making sure they talk to other young people about voting. “A lot of people think that you get young people to the polls by hiring a rock band and getting them to say something between songs,” he said. “If you want to get young people to vote, you need to talk to them where they live and where they hang out. This is where you do voter education, remind them where the polling place is, when Election Day is, and this works. Strategies that don’t work are celebrity endorsements. That kind of stuff is not as effective.”

The McCain campaign is also trying to attract young Republicans for the election. The youth spokesman for the campaign, Joe Pounder, said the campaign boasted “youth chairs” in all 50 states aimed at establishing networks for the counties of those states. Also. the campaign has launched an interactive Web site called Generation08 that encourages users to post their own videos and material.

Mr. Pounder questioned the widespread view that Mr. Obama was the candidate of America’s youth. In a sarcastic tone, he said: “The question I get is, ‘How are you guys going to compete for the youth vote with Barack Obama? He is so great with young people.’ But his organization, as we saw in the primaries, failed to translate that into votes. Where were his youth votes in Pennsylvania, Ohio, West Virginia during the primary?”