THE SNOWMOBILE BELT:

McCain and Palin Have an Opportunity in the Frozen North (Michael Barone, 9/22/08, US News)

[T]he reshuffling of the political deck seems to have opened up more states for McCain and have closed off some states for Obama, specifically, in the northern tier of the country: call it the Frozen North. Wisconsin, Minnesota, and Washington seem to be in play now. Preconvention polls showed Obama well ahead in each; postconvention polls show him leading by only a few points. That's 31 electoral votes on the table. And North Dakota, Montana, and Alaska seem to be out of play. Obama was competitive there in pre-convention polls, though there weren't many of them; he's well behind in postconvention polls. That's nine electoral votes off the table. Net advantage to McCain: 40 electoral votes. The Obama campaign has evidently reached the same conclusion: It is closing its North Dakota offices and the sending staffers to Minnesota and Wisconsin.

The obvious explanation, and not just for Alaska, is Sarah Palin.