FiveThirtyEight.com: Electoral Projections Done Right

FiveThirtyEight.com: Electoral Projections Done Right

Just one interesting point. If EITHER candidate can sweep the Ohio/Pennsylvania/Florida trifecta, he's in. If Obama does it, his chances of winning are 100%. If McCain does it, his chances of winning are 98+%.

The difference between those two scenarios is that Obama can afford to lose one or even two, but McCain cannot. If Obama loses Ohio, he still has a 78% chance of winning. If he loses Ohio and Florida, he's still at 66%, but if McCain loses EITHER Florida or Ohio, his chances drop to zero. Therefore, either candidate wins by taking all three of those states, but McCain pretty much has to win all three, while Obama has other routes to the Oval Office.

There are no really reliable numbers for Pennsylvania at the moment. Ohio and Florida seem to be a toss-up.