BERKELEY, Calif. — In the contest for the votes of young Democrats, Senator Obama of Illinois has some indisputable advantages, but another contender for the party’s presidential nomination, John Edwards, is determined not to cede the youth vote without a fight.

Mr. Edwards is on a cross-country college tour to appeal to students and liberal activists who can form the energetic core of a presidential campaign. The former senator from North Carolina and 2004 vice presidential nominee is set to appear at the University of California at Los Angeles this evening. Yesterday, at an event just off the Berkeley campus, he railed against the growing social inequality in America.

“Where is our soul? Where is our soul?” Mr. Edwards thundered as he lamented an economic boom that he said was leaving many citizens behind. “The growth is among the wealthiest Americans and multinational corporations. They’re doing great and no one else is.”

Mr. Edwards portrayed the Iraq war as a terrible misadventure and he warned that President Bush’s plan to boost the number of troops would only worsen the situation. “Putting more American men and women into this meat grinder is a tragic mistake. We cannot do that,” the candidate said.

Mr. Edwards, who is making a strong play for the support of labor groups, would not appear on the university’s grounds because of a dispute between the school and unionized custodians there who want higher wages. So several hundred students, faculty members, and other Berkeley denizens packed a small, overheated function room at a nearby YWCA. Hundreds of others who could not get in spilled onto the sidewalk and a nearby lawn, where they listened to loudspeakers.

Mr. Edwards’s in-person appeal seemed to have the intended effect on one Berkeley freshman in attendance, Benjamin Zaehringer, 18. He said that before the speech he was in Mr. Obama’s camp. “I had decided he was the voice of change,” Mr. Zaehringer said.

However, the Ventura, Calif., native said he was having second thoughts after seeing Mr. Edwards in the flesh and hearing him talk about his commitment to eradicating poverty. “Right now, I’m thinking Edwards looks very attractive. People really need to hear him speak,” Mr. Zaehringer said. He said Mr. Obama has a big following on campus, but that students have some misgivings. “They think Hillary Clinton can win, but Obama should win,” he said.

Mr. Edwards’s campaign has made a determined effort to appeal to younger voters. Its home page features links to nine social networking and content-sharing Web sites. Mr. Edwards also has formed his own service group, OneCorps, in an attempt to harness the popularity of public service work among young people.

However, it appears by some measures that Mr. Edwards’s careful plans have been swamped by the juggernaut of spontaneous student support for Mr. Obama. His Facebook.com group, set up by a fan months before the formal bid, now boasts more than 312,000 members. Senator Clinton’s largest group on that site numbers a little over 4,100 people, while Mr. Edwards’s fans are spread over several smaller groups. The former senator does have about 12,000 friends on MySpace.com, but Mr. Obama has about four times that.

There is little public polling data breaking down preferences in the presidential race by age. However, some surveys suggest that Mr. Obama’s appeal is highest with younger voters and drops off precipitously with older Americans. In a survey of Democratic and Democratic-leaning voters taken last month for the Pew Research Center, 52% of respondents under 30 said there was a “good chance” they would vote for the Illinois senator, but only 32% of those over 65 made that statement. Openness to Mrs. Clinton and Mr. Edwards was more consistent across age groups, though the pair got a somewhat better reception among older voters.

Whether Mrs. Clinton, who will turn 60 this year, can become the candidate for liberal young people is unclear. If youth is the sole factor in appealing to youth, Mr. Obama, 45, has the inside track. Mr. Edwards, 53, who was seen by many as too youthful when he ran for president in 2004, now finds himself somewhere in the middle.

The generational divide looms even among those who have been out of college for a few years. A basketball commentator for CBS Sports, Seth Davis, 36, has swooned over Mr. Obama, while Mr. Davis’s father, Lanny, 61, is a longtime friend of Mrs. Clinton’s and is supporting her bid for the nomination.

“I’ve never felt this way about a politician. I feel like this man speaks to me on an extremely direct and personal level,” the younger Mr. Davis said of Mr. Obama. “I believe he speaks to my generation the way JFK spoke to my dad’s generation. I remind him of that every time he tells me Obama is not experienced enough.”