Obama himself attended an IAF training, and contributed a chapter to the book After Alinsky: Community Organizing in Illinois. Neither the chapter nor Obama's memoir Dreams from My Father (which deals extensively with his time organizing) mentions Alinsky by name.
One of the few places where Obama has directly commented on Alinsky was in a profile by Lizza in 2007. Lizza writes that Obama internalized the first main lesson of Alinsky — that organizing is about leveraging the community's self-interest for its own empowerment. "The key to creating successful organizations was making sure people's self-interest was met," Obama told Lizza, "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." Eventually, Obama got the strategies well enough to teach trainings himself.
Hillary Clinton writes:
"For my thesis, I analyzed the work of a Chicago native and community organizer named Saul Alinsky, whom I had met the previous summer. Alinsky was a colorful and controversial figure who managed to offend almost everyone during his long career. His prescription for social change required grassroots organizing that taught people to help themselves by confronting government and corporations to obtain the resources and power to improve their lives. I agreed with some of Alinsky's ideas, particularly the value of empowering people to help themselves. But we had a fundamental disagreement. He believed you could change the system only from the outside. I didn't. Later, he offered me the chance to work with him when I graduated from college, and he was disappointed that I decided instead to go to law school. Alinsky said I would be wasting my time, but my decision was an expression of my belief that the system could be changed from within."
“Lest we forget at least an over the shoulder acknowledgment to the very first radical: from all our legends, mythology and history (and who is to know where mythology leaves off and history begins - or which is which), the very first radical known to man who rebelled against the establishment and did it so effectively that he at least won his own kingdom - Lucifer.”
― Saul Alinsky, Rules for Radicals: A Pragmatic Primer for Realistic Radicals