The first debate is NOT as clear as it first appears.
1. Romney was already getting positive traction before the first debate... so it's hard to determine how much was natural movement and how much was clearly debate-related.
2. Whatever movement Romney got was muted by the 'good' economic numbers straight after, it took almost a week to see the full impact of the bounce... which was not a 'bounce' it was movement.
The underlying point is that Romney's base was already coming home by the start of the first debate. In fact, the overwhelming response to the first debate accelerated a process already taking place. It excited the GOP base and moved some independents and undecideds into the Romney camp.
It's a bit like the smaller 'bounce' people say Obama got after the 2nd debate... but it's clear he was already re-gaining ground before the debate.
In hindsight, losing that first debate will probably be seen as an absolute God-send for Obama.
Couldn't Obama have demolished Romney to the point of no return had he won that first debate, though?