From Nate Silver:
Then there was Colorado, a state that has reasonably similar demographics to Nevada, which Mr. Romney carried easily on Saturday. Colorado has somewhat fewer Mormon voters than Nevada, which hurts Mr. Romney — but it has somewhat more wealthy ones, which favors him. The betting market Intrade gave Mr. Romney about a 97 percent chance of winning Colorado entering the evening. But he lost the state by 5 points to Mr. Santorum.