Wayne Allen Root has written on exactly this.
Mr.Root was at Columbia and in Obama’s exact class:
“Root tweeted that he was attending pre-law classes as a political science major — like Obama, supposedly — but that never saw the future president. Obama was my college classmate. Never met him, saw him, heard of him. And I don’t know a single classmate who ever met him either. I repeated this story hundreds of times.”
Mr. Root said he asked his fellow students years later at a reunion if any of them had ever met or even had a class with Obama - to a person they said “no.”
Obama is known as the “Ghost of Columbia.”
I have heard this story multiple times. George Stephanopolis is on record of not recalling him either. He was in the same class as Root.
Then when he was at Harvard Law he was made the President of Harvard Law Review.
A no show college student.