I would be hesitant to ascribe any real meaning to the Iowa results - they are, after all, the product of an obsolete system in an unrepresentative state - but looking at how the prediction markets reacted, it seems like there's an awful lot of uncertainty in who is going to be nominated:
Given the massive volume of polls that had come out, a move of this magnitude in the market says to me that a lot can happen. Though I guess political markets are the first place one looks for animal spirits.
NOTE: Image from Intrade. Click to expand.
UPDATE: If anyone knows a good text that covers Hamiltonians, please feel free to leave a comment. I was surprised that Simon and Blume had nothing.