The Obama ads running in northern VA have been SO negative. I think people are really getting tired of it. Just like BHO said in 2008, when you've got nothing, attack the other guy.
Frankly I'll still be surprised if Romney wins but the fact that he now has a shot speaks volumes. If the Dems screw this up it will only barely outshine the Republicans utter deafness on stupid social issues.
It's a lot easier for the government to turn honest citizens into criminals than criminals into honest citizens.