That was the question that plagued me as I studied the debate and reviewed audience Tweets or listened to the post debate commentaries. The only conclusion that I can reach is that the President and his supporters were confronted with something far worse than a personal loss. They were confronted with the fact that they have no record to run on. They have no message except to blame their predecessor or attempt to libel their opponent.
The moderator attempted to help the President by phrasing every question in a way that invited him to define his opponent's positions and proposals and then differentiate his. He began each topic saying, "What are the differences between you and your opponent." How else could anyone respond but by first defining the opposition?
Obama used this opportunity to misstate Romney's proposals in the same terms that have been used in his attack ads. Much to his credit, Romney didn't attack Obama, he attacked his record. He cited irrefutable facts that clearly demonstrate that Obama's progressive principles have failed as when he stated that "Trickle down government is the flood of your failed policies." When Obama complained that subsidies to "fat cat" corporations, such as $2 billion per year to oil companies, indicate misplaced priorities and that budgets reflect "where your heart is", Romney correctly observed that his Administration has invested "$90 billion in green jobs - that's the equivalent of 45 years of oil subsidies."
In the past, debate moderators have protected Obama from such attacks. Jim Lehrer tried it just once in the beginning and Romney brushed him aside to press his attack. Throughout the debate, the President looked away from the audience and his opponent, as Romney attacked other failures of this Administration.