CHARLESTON, S.C.—Sen. John Edwards captured a must-win victory here last night, capturing the South Carolina Democratic primary by a margin of 15 points over Sen. John F. Kerry, his nearest competitor.

But the Massachusetts senator cemented his place as the frontrunner for the Democratic presidential nomination with victories in five states across the country, including a major win in delegate-heavy Missouri.

The South Carolina vote “keeps [Edwards’s] candidacy alive, and keeps him viable for the vice presidential spot,” said Institute of Politics Director Daniel R. Glickman.

Twenty-two Harvard students joined the political frenzy here over intersession, flying down from Cambridge to volunteer for four presidential campaigns. The trip was partially funded through the Institute of Politics and was organized and sponsored by the Harvard College Democrats (HCD).

“We wanted to give people a feel for real campaigning, especially presidential primary campaigning,” said HCD President Andrew J. Frank ’05, who volunteered for the Edwards campaign here. “We had the resources to do it.”

South Carolina was a critical test for Edwards. The state garners national attention as the first primary held in the south and is also Edwards’ place of birth. A heavy investment of funds and time helped Edwards fend off a last-minute surge by Kerry.

Elsewhere, Kerry easily took the Missouri primary with 51 percent of the vote, while Edwards came in second with less than half that total. Gen. Wesley K. Clark took Oklahoma by a slim margin—almost 1,300 votes—last night.

In South Carolina, Edwards had received 45 percent of the ballots cast here yesterday with 94 percent of precincts reporting.

Kerry was in second place with 30 percent of the vote.

The Harvard volunteers have been working on the campaigns since their arrival in Charleston last Thursday. Students fanned out into various areas of the city to canvass, knocking on doors and distributing literature about their respective candidate. Though canvassing and publicity were the major activities of the week, students also helped phonebank and organized campaign activities.

Frank passed the afternoon of election day at a local taxicab station.

All of the campaigns offer voters a ride to the polls to help draw out support. Frank was the day’s “dispatcher” for the Edwards camp; residents were encouraged to call the campaign office, which would then arrange a ride with a taxi.

“To be honest, I’m just sitting around,” Frank said.

Kerry Triumphant

In the rest of the country, Kerry carried the day, according to political experts.

“You cannot underestimate Kerry’s wins tonight,” Glickman said. “Kerry remains the strongest candidate. His speech tonight was exceptionally powerful.”

Even so, Kerry’s supporters in South Carolina had hoped for a win in the state.

“For the amount of time Kerry has been in this state to do so well, it shows how electable he really is,” said Kerry supporter Lakshmi Sridharan ’06, who volunteered here for the campaign over the past week.

As the Kerry and Edwards campaigns gathered momentum from yesterday’s results, Sen. Joseph I. Lieberman’s efforts sputtered to a close.

Lieberman exited the race after a disappointing showing in Delaware.

Former Vermont Governor and onetime Democratic frontrunner Howard B. Dean was polling in fifth place in South Carolina at press time, trailing behind the Rev. Al Sharpton and Clark.

“Nobody’s happy about it obviously,” Greg M. Schmidt ’06 said of Dean’s showing.

An HCD officer and Dean supporter, Schmidt volunteered for the campaign here this week. But Schmidt noted that Dean had decided to bypass last night’s slate of primaries and look ahead to Michigan and Washington.

Climenko Professor of Law Charles J. Ogletree, an adviser to Sharpton, said the candidate’s third-place showing was proof that Sharpton “has to be taken seriously.”

“[Sharpton] continues raising issues that matter to a broad segment of the community that feels disenfranchised,” Ogletree said.

“He continues to be a persistent factor” in the race, Ogletree said.

Harvard in Charleston

Polls opened at 7 a.m. yesterday morning in SouthCarolina, and the campaigns got into gear early.

The Dean volunteers were up first, meeting at their downtown headquarters at 5:45 a.m.

According to David C. Marshall ’07, the group then traveled to an “undisclosed location” in Charleston for a strategy meeting with the entire local Dean staff. A fire alarm went off as the meeting was about to begin, leading some staff members to suspect foul play on the part of rival campaigns, Marshall said.

By 8:30 a.m., the Harvard volunteers on the Dean staff were dispersed throughout the downtown area here, wielding campaign signs and stickers to promote “poll visibility”—which required standing outside voting places and hawking candidates to Charlestonians on the way to cast their ballots.

Marshall, who was assigned to the College of Charleston voting place, was “expecting some high-tech voter thing,” but was surprised to find a relatively simple operation. This veteran Deaniac—who worked briefly for the campaign in New Hampshire— had been instructed to report a vote tally from the polling place every two hours.

Around 7:30 a.m., Kerry’s Harvard volunteers arrived at their offices, located two floors below the Dean headquarters.

Workers were immediately sent out on “lit-drops” around the city, leaving flyers and candidate information on parked cars and in stores and restaurants. Visibility was a high priority as campaigners hoped to capture the ballots of still-undecided voters.

Jonathan D. Einkauf ’06, who is working for the Kerry campaign here, demonstrated some of the more irreverent tactics the Harvard contingent brought to the South Carolina.

After taping a large Kerry poster onto a wall outside of a Food Lion grocery store, Einkauf was confronted by an employee.

“That’s gotta go,” the man said solemnly.

After attempting to negotiate for a moment, Einkauf relented and took the sign down. The employee thanked him and turned away, but Einkauf immediately posted the sign right back up, this time on a wall facing away from the store.

Giggling, he walked back toward the rest of the Kerry workers.

“He’ll notice it when he’s going home for the day,” Einkauf said.

The Edwards camp, which started the day at 7 a.m., was divided into small groups and dropped off at intersections to campaign during morning rush hour. At 9 a.m., the workers planned to return to Edwards-friendly neighborhoods and ensure that “all the Edwards voters we know of are going to vote,” said Paul C. Davis ’07.

Frank said the Dems chose to campaign in Charleseton because of a combination of political and aesthetic reasons.

“We wanted to be in a place where we could have a big impact,” Frank said. “Columbia is very cluttered, and we wanted to be in a nice location.”

—Staff writer Michael M. Grynbaum can be reached at grynbaum@fas.harvard.edu.