Mitt Romney’s narrow paths to the White House

Can Mitt Romney win the presidential election on Tuesday? The answer is yes, he can — but it’ll be tough. Although the national polls taken in isolation suggest the race is roughly tied, the state-level polling points to a much bigger lead for Barack Obama. It seems that either the national polls are underestimating Obama’s strength or the state polls are overestimating it, or both. Nate Silver’s Fivethirtyeight model  assumes it’s both, so adjusts the national polling slightly towards Obama and the state polls slightly away from him, so they meet in the middle. And that leads it to forecast a win for Obama of slightly more than two points. That sort of margin would more or less guarantee the President re-election.

Romney’s hope, then, is that the state polls are heavily overestimating the President’s support, and that the race is pretty much tied as the national polls suggest. To be clear, there’s no more reason to believe this than to believe that the national polls are heavily underestimating Obama and he’s actually leading by more like four points.