Winning the Small States Would Give Obama Options

One interesting feature of the FiveThirtyEight model is that it doesn't just calculate a point estimate for the popular-vote margin in each state, it also calculates a margin of error for that estimate. And this isn't simply some assumption based on how far in the distance the election is; rather, it's derived from the data available in that state, with I think the most important component being the amount of polling available in each state. The intuition is fairly simple: if a state has been polled to death, we have a better sense of the state of play there, and ought be more confident in our predictions regarding that state, than if there have only been a handful of polls. Part of what that means for 2012 is that Ohio, which has been polled to death, has a rather small error bar around its forecast, as can be observed from the "Competitive State Summary" in this article.

The fact that, in particular, Ohio has a much more confident forecast than Iowa or New Hampshire means that the order of the states by Obama's likelihood of winning them is not the same as Obama's order of states by Obama's expected margin in them. So if you draw up a path-of-least-resistance map based on the 538 odds, you add in all the 90%+ states, and then Wisconsin, and then Nevada, and you're at 253 electoral votes, and then Ohio and you're at 271 and Obama wins. But if you construct a path of least resistance map based on the 538 margins instead, after Nevada's 253 you next toss in Iowa and New Hampshire, getting to 263. Now, since the next state on your list is Ohio, which would've been the tipping-point state anyway by the other method, Iowa and New Hampshire are redundant, and so the path of least resistance is probably  basically the same by this method: you add on Ohio, get up to 281, and then ditch Iowa and New Hampshire as superfluous.

But that doesn't mean the fact that Obama's margins in Iowa and New Hampshire are larger than that in Ohio couldn't be relevant. Consider this map:

The dark blue states are those Obama leads by at least 3 points on the current FiveThirtyEight forecast, which total 253 electoral votes. The light blue states are, well, Iowa and New Hampshire, the two other states Obama leads by more than he leads Ohio. The red states are those Romney leads in, and the purple states are those Obama leads in but not by more than in Ohio. If you only give Obama the dark blue states, then he must add Ohio or Colorado and Virginia in order to be victorious. But if you tack on Iowa and New Hampshire, giving him a base of 263, then Ohio or Colorado or Virginia would do it. Ohio would get him to the highly-superfluous 281, Virginia would get him to 276, in which case he could jettison one of IA and NH, and Colorado would put him at 272.

Winning these small states, which for whatever it's worth happen to be the two most important primary states, in other words, gives Obama an extra degree of flexibility. They would allow him to win with his Midwest firewall, his Southern firewall, or his Western firewall, any one of the three. So while Iowa and New Hampshire are superfluous for purely path-of-least-resistance purposes, they matter a great deal in terms of the number of relatively easy paths to victory available to Obama.