33,
It's looking a lot like ROmney could win the popular vote yet not get enough states to win the electoral. I mean, Romney has to win, what, 7 of the 9 swing states in order to take the election? That's a huge order. That explains his 13% Nate Silver prediction. He may have 51% of national vote, and only 6 of the 9 swing states and lose.
It's a very real possibility. There's also the possibility that non-white voters are being under-sampled. Living with disposable phones, obama phones, recharge phones from walmart... i mean, many people can't afford a $150 iPhone bill, and who has land lines under the age of 30?