Saul Alinsky was a founder of modern community organizing. He wrote several books on the subject, and was the head of an influential community organization in Chicago. The commitment to social justice that inspired many secular Jews in the past -- and still does, I would say -- is among my greatest criteria for choosing my heroes.
I consider it to their credit that Obama and Hillary Clinton were associated with Alinsky's group. The fact that extreme right wing nuts find that alarming just makes me like him (and them) better. Hillary Clinton received a job offer from Alinsky in 1968 when she was in college; she turned it down, though she wrote her senior thesis about him. Obama worked for an offshoot of Alinsky's group; however, Alinsky had died by the time Obama arrived in Chicago.
Alinsky, according to Marian Wright Edelman, the Children's Defense Fund leader, "was brilliant. He was working for underdogs. He was trying to empower communities, which we still need to do. He spoke plainly. He had his outrageous side, but he also had his pragmatic side. Both Hillary and Barack reflect that understanding of community-organizing strategy. Both just know how to leverage power." (Quote from "For Clinton and Obama, a Common Ideological Touchstone," Washington Post, March 25, 2007.)
I don't ordinarily use Wikipedia, but I found it interesting regarding his view of his Jewish background. According to what I found there, Alinsky considered himself to be a devout Jew until the age of 12, after which time he began to fear that his parents would force him to become a rabbi. "I went through some pretty rapid withdrawal symptoms and kicked the habit. . . . But I'll tell you one thing about religious identity," he added. "Whenever anyone asks me my religion, I always say—and always will say—Jewish."