Nate Says. . . . .

Here's where to watch:

This is beginning to look like a five-state election. Those states are Virginia, Colorado, Pennsylvania, Ohio and Nevada. Essentially all relevant electoral scenarios involve some combination of these five states.

I should caution that by far the most likely scenario is that Obama wins some relatively decisive victory of anywhere from 3-12 points in the popular vote. If Obama wins the popular vote by anything in this range, he will find plenty of blue territory, accumulating somewhere between 300-400 electoral votes. The electoral math will matter very little.

We can probably assume, however, that IF the national polls tighten significantly (and to reiterate, the likelihood is that they will NOT), McCain will edge out a victory in North Carolina, Florida, Indiana, North Dakota, Montana, Georgia, and Missouri; put those states in the McCain column for the time being. Likewise, New Mexico, New Hampshire, Minnesota, Michigan, Wisconsin and Iowa all appear safe for Obama, even in the case of significant tightening. Put those in the Obama column.

That leaves our five states in play. The victory conditions for Obama involving these five states proceed something as follows:

1. Win Pennsylvania and ANY ONE of Colorado, Virginia, Ohio, or Nevada*
2. Win Ohio and EITHER Colorado OR Virginia.
3. Win Colorado AND Virginia AND Nevada.

(* Nevada produces a 269-269 tie, which would probably be resolved for Obama in the House of Represenatives.)

Now, suppose you think that Colorado is already in the bag for Obama because of his large edge in early voting there. We can then simplify the victory conditions as follows:

1. Win Pennsylvania
2. Win Ohio
3. Win Virginia AND Nevada

That's basically what it comes down to, although I'm sure each campaign would claim that there are a larger number of states in play.