It's more the masturbatory media narrative than the actual debate.
Is the media really talking all the day about Romney's amazing energy, charisma and presidentiality, while rambling on Obama's utter ineptitude, emptiness and arrogance? Because I can't otherwise explain a 7-point shift in a race that has otherwise been unmovable all along.
The explanation is white swing voters desperately wanted to shift, and were looking for a reason, any reason. Or to put it another way, they were looking for any reason to excuse Romney's obvious negatives (class enemy, etc).
Or this is the first unfiltered look the American public has had at Romney since he became the nominee and they liked what they saw.
The Obama Campaign had a $100 million dollar free run at knocking Romney down and all they have left is "Lying liar who lies... what? why would you ask me for an example" and "Big Bird".
The media will do all they can to prop up Obama, but their are limits. They can't risk the complete destruction of their credibility. Amazing what a little fair coverage will do to perception. These shifts were predictable and many saw them coming. If anything the question is:
How did Obama stay propped up this long?
not,
This is ridiculous, what happened?