Organizers described themselves as the antidote to big-money lobbyists who wield so much influence. They talked about helping powerless people join forces to demand better schools and safer streets, often by working through churches.
"If people in office were doing their jobs, perhaps we wouldn't need community organizers," said John Baumann, executive director of PICO National Network, whose name derives from "people improving communities through organizing."
"I don't like seeing the really hard work that goes on in really poor communities being demeaned by cheap politicians," said Joshua Hoyt, executive director of the Illinois Coalition for Immigrant and Refugee Rights. "Community organizing is as American as democracy. It believes that ordinary people can do extraordinary things."
Obama, the Democratic presidential nominee, has often talked about his three years as a community organizer in Chicago. He uses it to demonstrate that he understands the problems of people losing their jobs and stuck in deteriorating neighborhoods.
Republicans belittled his organizing experience Wednesday night.
Former New York Mayor Rudy Giuliani began summing up Obama's experience by noting he had worked as a community organizer. "What?" he said, with a tone of disbelief. "Maybe this is the first problem on the resume," Giuliani said.
Vice presidential candidate Sarah Palin touted her credentials as mayor of an Alaskan town. "I guess a small-town mayor is sort of like a community organizer, except that you have actual responsibilities," she told the cheering crowd.
Several organizing groups condemned the remarks.
John Raskin, who works to make low-income housing available in New York city, quickly launched a Web site, "Community Organizers Fight Back," to respond. It attracted scores of responses Thursday from organizers upset by the criticism.
"I just think it's adding insult to injury," Raskin said of the Republican comments. "First, to create an economy that leaves out so many people and then to insult people who are trying to help."
Obama even raised the issue in a fundraising appeal to supporters, saying that "Republicans mocked, dismissed, and actually laughed out loud at Americans who engage in community service and organizing."
McCain spokesman Tucker Bounds said Palin's comment shows she is "too tough to be pushed around" by the Obama campaign's criticism of her experience.
Organizers describe their work as identifying potential leaders in a community and then helping those people tackle local problems. They research possible solutions, teach people how to figure out who can help and how to explain their concerns, then try to pressure the powerful into taking action.
Some organizations set up their own community groups, but most work with existing institutions, often churches.
Baumann said their concerns might be as basic as getting rid of a drug house or having more police patrol their neighborhood. Organizers also help set up job-training programs, push for better parks and streets, and press for school improvements.
"I basically think of it as very conservative. People are concerned about their families and ... the vehicle for that is through organizing," Baumann said. "The importance of assisting people improve their own lives - it's quite a responsibility."
Dave Beckwith, executive director of The Needmor Fund in Toledo, Ohio, said it would be wrong to assume community organizers and the people they help are all liberals. They include both Democrats and Republicans and their work can involve clashing with politicians from both parties, he said.
"This is an election that I understand to be about the middle," Beckwith said. "People active in community life and who have aspirations for their communities - it seems to me that anyone would want to speak to those people respectfully."