CAMBRIDGE, MASS. — Forty years ago Marshall Ganz, a top field organizer for Cesar Chavez's United Farm Workers union, watched in confusion as Bobby Kennedy left a stage at Los Angeles' Ambassador Hotel.
Ganz was supposed to whisk him away to thank a roomful of farmworker volunteers who had just helped him win the 1968 California Democratic presidential primary. But Kennedy was heading toward the kitchen.
Before Ganz could catch up, the room erupted in screams and yells. Robert F. Kennedy had been shot.
"Talk about feeling history just falling through your fingers," Ganz said.
Ganz is sitting at his kitchen table as he tells the story, one in a series of personal narratives from his life as a rabbi's son in 1950s Bakersfield, a civil rights worker in Mississippi in the 1960s and, later, a key figure in the United Farm Workers' boycotts.
They are stories of faith and betrayal, love and hate, hope and disillusionment.
And if Barack Obama succeeds in his historic quest for the White House, the Illinois senator will owe a large debt to Ganz's passion for such narratives -- and for the way this graying, portly man taught Obama's top field organizers to weave thousands of individual volunteers' stories into a social movement.
Ganz, 65, has no official role in the Obama campaign. But when key Obama organizers run into a problem, they look to Ganz, who teaches organizing and leadership at Harvard University's John F. Kennedy School of Government.
When the Obama campaign held a series of "Camp Obama" training sessions around the country last summer, Ganz was brought in to hold two-day discussions of personal narrative and leadership.
Campaign officials estimate that 200 to 300 organizers were trained at about a dozen Camp Obamas -- three of them co-led by Ganz.
The effort's biggest success came in caucus states like Iowa, where tightknit organizations were better able to get people to the meeting sites.
But grass-roots efforts also paid off in South Carolina and Wisconsin and helped keep the margin small in Indiana.
Ganz's "style of organizing really does speak to who Barack is as a candidate," said Obama field organizer Buffy Wicks, 30, who ran the campaign's grass-roots efforts in California and Texas.
"Marshall really believes in empowering people and teaching them how to become community organizers."
Maggie Fleming, who attended a Camp Obama last summer, said: "Marshall is able to bring this bigger picture of his work with civil rights and with the farmworkers and [connect] people to this idea that this is bigger than just one candidate."
Fleming, 28, the assistant director of a nonprofit environmental education group, later helped form the core of Obama's grass-roots committee in Oakland.
Ganz encourages volunteers to share their own life stories with voters, in the belief that by speaking from the heart, they turn the tedious -- phone-banking, door-knocking -- into a communal mission. It's not policy but passion that he teaches.
"It's counterintuitive," Ganz said. "At Camp Obama the tendency is, 'I need to know all of the arguments.' No. You need to learn to talk from your own experiences. It's a very empowering thing."
For Ganz too. He sees the campaign as a chance to turn back the hands of time.
Ganz was born in Bay City, Mich., and grew up in Fresno and then Bakersfield.
He entered Harvard in 1960 but after two years took some time off. When he returned to Cambridge, he found that one of his roommates had joined Students for a Democratic Society and another had joined the Student Nonviolent Coordinating Committee.
He volunteered for the Freedom Summer of 1964 in Mississippi and was in training when volunteers James Chaney, Andrew Goodman and Michael Schwerner disappeared. They were found dead several weeks later.
Ganz decided to forge ahead -- and found his life's work.
"I had friends involved in SDS, and they would have these big ideological discussions, which never had any appeal to me," Ganz said. "What worked for me was to work with the people, going around and meeting people."
As a way to connect with the black community, the rabbi's son taught adult Sunday school in Mississippi -- Old Testament only. Ganz returned to the Central Valley in 1965 and soon joined Chavez's fledgling farmworkers union, where he helped organize workers, lead boycotts and negotiate contracts until internal divisions led him to quit in 1981.
He then moved into political organizing full time, targeting infrequent voters.
The strategy turned out 180,000 new voters, primarily in low-income Latino and black neighborhoods, who helped Sen. Alan Cranston win a tight reelection battle in 1986.
In 1991, 28 years after he left, Ganz was back in Cambridge, where he earned a master's degree and, in 2000, a doctorate and then marked another transition: from student to teacher.