A fascinating interview with someone who knew Barack Obama at Occidental College, and was a fellow Marxist at the time, can be heard here. Dr. John Drew is interviewed by frequent AT contributor Paul Kengor, as he guest hosts the Glen Meakam Show.
Drew was founder of the Democratic Student Socialist Alliance at Occidental - basically, the Marxist club, as he describes it in the interview. He got to know young Obama fairly well, and notes that Obama described himself at the time as a Marxist-Lenninist, and anticipated a revolution in the United States.
To listen, click on "play now" following the words "Standard Podcast" at the top of the page, and scroll to 41 minutes on the podcast scroll bar that will appear as the podcast loads.
Drew notes that he has not been interviewed by the major biographers of Obama. I have little doubt as to why.