He doesn't have a choice.
If Romney loses Ohio, he has to take NH, Iowa and Nevada to make up for it. It can be done, but it seems unlikely. Hell, even if he takes Ohio he needs to hold Colorado and Florida while winning Virginia.
The electoral college remains a nightmare. Without Ohio in his pocket, it's less of a nightmare and more of a deathblow.
"If there's a god, he's laughing at us.....and our football team..."