Problem here is Obama is trying to stick to acting like an adult, making his points slowly, carefully, and then ramping up bit by bit. He's acting like a sitting president.
Romney knows this is his last shot to stoke fresh fire behind himself, so he's desperately clawing at everything around himself like a maniac. Hoping that will be taken as passion and drive. Judging by a lot of the impressions here, the trick works.
Romney knows his only shot is a final appeal to people who are afraid and want to believe he's the one to lead them away from the devil president even if Mitt has absolutely nothing.