This CBS story where
"experts" claim the debate was a tie is a perfect example of why so many people in the soft sciences don't really understand science.
The job of a scientist is to explain the facts in front of them. In the face of three polls which clearly show that Kerry won the debate, CBS's political "scientists" instead choose to explain the facts away. They claim the debate is a draw but then offer no evidence to support their claims.
Reading the CBS article critically shows that the only thing we know for sure is that political "scientists" have no way of really predicting what will happen next. They have no models, no testable predictions, nothing that even closely approximates the scientific method.
The only fact that can be agreed on at this point is that the polls show that viewers of the debates judged by wide margins that Kerry won and Bush lost. Anybody who says they know more is just spinning.