Adam Nagourney notes the Obama camp's vastly superior Iowa expertise. And in my experience, those guys do have a stunningly deep knowledge of the minutae of the state that dates back decades.
But Hillary has a much bigger problem on her hands. When you caucus, you don't just dump a secret ballot into a slot. Caucuses are social events and individual decisions on caucus night are shaped by social pressures. Gephardt veterans like to describe how their 2004 free fall occurred in the moments between the time that caucus-goers parked their cars and sat down to do the evening's business. That's when they encountered the enthusiasm for Kerry and Edwards with their own eyes; they grew ashamed to cast their votes for someone so seemingly fusty as Gephardt. Sticking with Gephardt became an act of social courage that stunningly few made--at least relative to his stronger pre-caucus poll numbers.
Clearly, Obama is shrouded in an excitement that Hillary can't match at present. So, how will Hillary's soft supporters respond when confronted with this excitement on caucus night? Will they hold firm to their commitment to Hillary in the face of this enthusiasm? Or will they decide to give into Obama as they make their way from the parking lot. Hillary is hardly doomed to a Gephardt-like crumble on caucus night. Enthusiasm for Obama could wane between now and January 3rd. And she could solidify her support. But if I were her people, I'd be worried about such a doomsday scenario.