My.02 is that Romney was going in with an advantage in that Obama was the incumbent with a record to defend. Romney was back against the wall based on his campaign performance and the polls. He had to come trumps. On the other hand Romney didn't really have much details to his proposals for the President to attack. Romney had the benefit of being able to say whatever he wanted and call it his policy details and Obama wasn't in a position to research and call him out on it unless it was blatant crap. The first Bush-Kerry debate had a similar vibe to it.
The second one will be more telling because Romney had to open his kimono and show his hand. So bet yuh money that Obama campaign taking everything he had to say and formulating rebuttals. I was kinda surprised how easily and boldface Romney changes his positions or denies previous positions for example him saying he not going to cut taxes by $5T and how he embraces Massachusetts health care after running from it like crazy during the primaries. Plus I seeing the fact checkers calling out Romney for being less that accurate.
Edit: Changed billion to trillion. Thanks for catching that Bakes.
