Some company publishes Alumni Directories for all the major colleges and universities. They publish one for my alma mater every ten years anyway and I know similar directories exist for Columbia. Several years ago I asked a Columbia graduate if Obama's name appeared in the Columbia directory and he said it did. It's just too much for me to believe that Columbia (which must be the source of alumni contact info - I get contacted by the publisher directly.) was somehow decided to play along with some Obama conspiracy before Obama was Obama. I think it's pretty certain that he has a degree from Columbia, though he probably attended classes there only during his senior year. (And maybe not many classes either. I'm pretty sure I've seen remarks from Columbia profs who remember him.)
ML/NJ
If what you say is correct, why is it that (1) no one in that Columbia graduating class in political science (or any major, for that matter) has ever stated that he or she remembers him (you would think that a light black guy from Hawaii would be remembered because of his unique demographic) and (2) he somehow managed to complete two years of course work in one?
One possibility is that Columbia gave him a phony unearned degree to qualify him for Harvard Law School several years later, under pressure from his Saudi benefactors.