In his memoir, Dreams from My Father, Obama identifies the roommate he had while attending Columbia, Sohale Siddiqi, only as “Sadik” — “a short, well-built Pakistani” who smoked marijuana, snorted cocaine, and liked to party. In 1981, during his college years, Obama traveled to Pakistan.

Obama’s campaign, AP reports, refused to further identify “Sakik” and his friendships in general. Nor will it discuss Obama’s years at Columbia. And it has not been forthcoming about the details of his trip to Pakistan.

Why not? Why are media pundits not pushing for more information about this period of Obama’s life?