So what does this map show us ? First, FTE's prediction were quite correct, because for only 12 states he was wrong by more than 5 points. Now, I've the impression that FTE underestimated Obama in the states where he won, and overestimated him in those where he lost ( that's rigth for every state excepted Iowa ), maybe due to an excessive ponderation of the polls. Moreover, if you except this fact, I think that FTE's margin of error corresponds to 2004-2008 trends : we can see that in states like Arkansas, Louisiana or Vermont. So, maybe FTE gives too much importance to past elections for its projections.
What do you think about it ?
I think your observation may be pointing to some of the statistical nature of a poll of polls. I think 538 had a solid, predictable method to their projections. However, even as 538 was prone to note the systematic leaning of some of their component polls, they also may have succumbed to some systematics.
As you note, the 538 projections tended too much toward the middle. This might be due to their averaging techniques, and this would be an interesting statistical study. A second factor may be the failure to identify undecideds and soft decideds as breaking more towards their state's eventual result than towards an even split.
Poll
