I've posted this probability here before; i.e., that barry in fact attended GS and not the "Ivy League" Columbia College. When I was at CC, we had a few transferees into their sophomore years, but it was very rare for CC to accept a transferee in his (it was not yet co-ed when I attended) Junior year; only the most brilliant students with impeccable credentials were even considered for acceptance as transfer students after spending two years at another institution.
By 1997, he appears under the name “Barack Obama” in the commercially-available 1997 edition all=Columbia alumni directory that’s supposed to include graduates of all the Columbia divisions. His address in the 1997 edition is an address in Hawaii. That’s the year he was sworn into the Illinois legislature. In the 2007 edition, he appears as “President Barack Obama,” White House, 1600 Pennsylvania Ave., Washington D.C. Given all his moving about, it’s surprising he got and answered his mail to update the data. Likely someone else did the updating for the recent edition.
There is no way that he would not have been remembered by people at Columbia College if he showed up for classes there. He is a memorable figure, even in his strung out years. He had help on the inside, likely with a request from the outside, to make an exception and give him the Columbia College imprimatur. Bill Ayers, now with his wife Bernardine Dohrn out of hiding, was during this period getting an undergrad education degree at Bank Street College of Education, located a few blocks south of Columbia University and then Ayers moved onto graduate study at Teacher’s College of Columbia University, a couple of blocks north of Columbia College. If Obama was really there at that time, there’s little chance all these radicals would not have known each other.