Nate Silver, our favorite political numbers-cruncher, SAYS it’s not likely that Barack Obama will do as well at the ballot box against Mitt Romney as he did against John McCain four years ago:
Although Mr. Obama is now the clear favorite in the Nov. 6 forecast, his advantage is larger in the FiveThirtyEight “now-cast,” which projects what would happen in an election held today.
The “now-cast” estimates that Mr. Obama would have a 97.8 percent chance of winning an election held today. Further, it pegs his advantage at five and a half percentage points in the national popular vote.
By contrast, the Nov. 6 forecast expects Mr. Obama to win by a smaller margin, 3.6 percentage points, on Election Day itself…
[But] the uncertainty in the forecast is symmetric: Mr. Obama is as likely to overperform it as underperform it.
If Mr. Obama misses to the downside by 3.7 percentage points, then Mr. Romney would win, at least in the popular vote. However, if Mr. Obama missed to the upside by 3.7 percentage point instead, he’d win the popular vote by 7.3 percentage points, exactly replicating his margin from 2008.
In other words, there looks to be about a 20 percent chance that Mr. Romney will win, but also about a 20 percent chance that Mr. Obama will actually beat his 2008 margin in the popular vote. The smart money is on an outcome somewhere in the middle – as it has been all year. But if you can conceive of a Romney comeback – and you should account for that possibility – you should also allow for the chance that things could get really out of hand, and that Mr. Obama could win in a borderline landslide.
Silver also offers this interesting chart: