The Reverend Jim Jones will always be remembered as the Ukiah-based cult leader who led 909 followers to their deaths in Jonestown, Guyana, having them drink from vats of poisoned Kool-Aid. Yet Jones, who established a branch of his Peoples Temple church in San Francisco shortly before the infamous 1978 death trip, had supporters outside his congregation – among them, some of the city’s most respected leaders.

In 1976, then-mayor George Moscone appointed him, briefly, to the city’s Housing Authority Commission, perhaps in recognition of the enigmatic reverend’s generous contributions and outspoken support. That same year, an up-and-coming state assemblyman, Willie Brown, was effusive in his praise of Jones, calling him “a leader with tremendous character and integrity.” Years later, Brown defended his position, arguing that the Messiah from Ukiah, as he was dubbed in 1972 by Examiner religion writer Les Kinsolving, masked his madness convincingly.

Stanley Nelson’s new documentary, Jonestown: The Life and Death of Peoples Temple, examines that madness, as depicted in rare video footage and described by survivors, but also the lofty ideals and seemingly progressive spirituality that attracted so many loyalists to the congregation. Nelson, a 2002 MacArthur Fellow and onetime Emmy winner, admits he didn’t know much about Jones before embracing the project. But a series of 2003 radio interviews with former Peoples Temple members piqued his curiosity.

“When I started this film three years ago, I knew what most people knew – that roughly 900 people followed this madman and committed suicide,” Nelson says. “What got me interested in the story was what I heard around the time of the 25th anniversary, when some of the survivors told their story. They talked about the only time they had ever lived in an integrated community, the only time they had lived out their ideals. They still talked about Peoples Temple with a great deal of love, and they all sounded so sane.”

Was that what kept them from leaving Jonestown sooner than they did, before members of their families could be persuaded to kill themselves at Jones’ command? Nelson needed to know.

“Clearly, Jones gave people something that they wanted,” he explains. “Even Hitler, as awful as he was, gave the German people something they wanted, at least early on. Obviously, [Jones] made them want to stay. He had a fascinating ability to attract such a diverse group of followers, so he had to offer different things to different people. For older people, black and white, he promised to take care of them better than social services ever would. And they would be part of a family. For others, he invited them to be part of a spiritual movement to change the world – and they didn’t think they were joining a cult.”

Problem was, they were joining a man who hid his madness, evident even in childhood, behind fiery sermons and promises of a groundbreaking utopian community. But the tragedy that unfolded could have been avoided, Nelson says, if opposing voices had made themselves heard.

“There is a lesson in the film that’s applicable to where we are today,” he says. “Jonestown didn’t happen quickly. It was a series of little things, and nobody stood up tp say, ‘This is wrong.’ The people who walked into that church the first time, smiling and singing, gradually changed and became trapped. It was a series of cuts and compromises. They didn’t happen overnight, and not enough people raised their voices in protest.”