The first and most fundamental lesson Obama learned was to reassess his understanding of power. Horwitt says that, when Alinsky would ask new students why they wanted to organize, they would invariably respond with selfless bromides about wanting to help others. Alinsky would then scream back at them that there was a one-word answer: "You want to organize for power!"

Galluzzo shared with me the manual he uses to train new organizers, which is little different from the version he used to train Obama in the '80s. It is filled with workshops and chapter headings on understanding power: "power analysis," "elements of a power organization," "the path to power." Galluzzo told me that many new trainees have an aversion to Alinsky's gritty approach because they come to organizing as idealists rather than realists. But Galluzzo's manual instructs them to get over these hang-ups. "We are not virtuous by not wanting power," it says. "We are really cowards for not wanting power," because "power is good" and "powerlessness is evil."

The other fundamental lesson Obama was taught is Alinsky's maxim that self-interest is the only principle around which to organize people. (Galluzzo's manual goes so far as to advise trainees in block letters: "get rid of do-gooders in your church and your organization.") Obama was a fan of Alinsky's realistic streak. "The key to creating successful organizations was making sure people's self-interest was met," he told me, "and not just basing it on pie-in-the-sky idealism. So there were some basic principles that remained powerful then, and in fact I still believe in."