In national surveys, Romney’s up by a median of +1.0+/-1.0% (n=10). Yet the Popular Vote Meta-Margin, which is nearly all caught up, is at Obama +0.84%. What accounts for the difference?
Normally I don’t engage in this kind of detailed combination-dissecting, since there are so many possibilities. The whole point of the Meta-Analysis is to avoid such activity. But it does illustrate the difficulties faced by a candidate, even when a race is very close. Also, the risk of nonmatched popular vote and electoral vote is a recurring theme in recent Presidential politics (2000 and 2004).
The Electoral College contains a structural advantage that favors Obama at the moment. Click the map once to get current probabilities, twice to get a version you can experiment with yourself. Interactive versions are also available in the right sidebar.
The most plausible paths for Romney at the moment are OH or hitting the double: a NV-WI combination. All three of those states have totally post-debate polls, and they are all blue. It would take a pretty hard push to drive the Meta-Margin to the red side. Possible, but something big (in addition to current trends) would have to happen. Watch the major candidates’ travel schedules.