In the wake of Super Tuesday, the Clinton/Obama faceoff is more confusing than ever. But an “X” factor could change the shape of the race: so-called “superdelegates,” Democratic party insiders who are the free agents of the primary season. Could the delegates throw the convention into disarray? The Nation‘s political correspondent Ari Berman, expanding on his recent piece about the delegate race, breaks down who these “superdelegates” are, and what they mean to the Clinton/Obama race.