Someone asked me a good question: would Obama have won without the financial crisis?
I think so, although the magnitude of the victory might not have been as great.
We started polling Virginia and Colorado regularly in June. Obama never trailed in one of our polls in either of those places, even right after the Republican convention when McCain was getting such a strong bounce nationally. It was certainly close in those states but even in those few days where America seemed to be in love with Sarah Palin, Obama was holding on.
Those two may well have been Obama's firewalls regardless of what happened elsewhere, and would have ensured 286 electoral votes.
Obama was losing in Ohio and Florida at the time the financial crisis got really bad but that was right in the wake of the GOP convention and it's unclear whether McCain's bounce would have receded in those places or not. The only places Obama appears to have won that might not have been on the table if the economy hadn't gotten so bad were Indiana and North Carolina, but you can still argue that his ground game in those places would have made him very competitive either way.