I was Barack Obama ’83’s roommate at Columbia College in fall 1981. I met him in 1979, when we were freshmen at Occidental College (Oxy) in Los Angeles and our dorm rooms were directly opposite each other. I came to college as a middle-class guy from Bethesda, Md., where I’d lived from fifth grade through high school. At Oxy, we attended some of the same social events and had late-night philosophical discussions related to our college reading or to current affairs. We attended rallies on campus where we were urged to “draft beer, not people,” and discussed the Soviet invasion...