Charles Franklin sets out the specific questions that need answers:
What we see for the Democrats is quite stunning. The polls actually spread very evenly around the actual Obama vote. Whatever went wrong, it was NOT an overestimate of Obama's support. The standard trend estimate for Obama was 36.7%, the sensitive estimate was 39.0% and the last five poll average was 38.4%, all reasonably close to his actual 36.4%.
It is the Clinton vote that was massively underestimated.... So the clear puzzle that needs to be addressed is whether Clinton won on turnout (or Obama's was low) or whether last minute decisions broke overwhelmingly for Clinton. Or whether the pollster's likely voter screens mis-estimated the make up of the electorate. Or if the weekend hype led to a feeding frenzy of media coverage that was very favorable to Obama and very negative towards Clinton, which depressed her support in the polls but oddly did not lower her actual vote.
The fact that it was an underestimation of Clinton's vote, and not, as some have suggested, an overestimation of Obama's, means we can safely eliminate one potential explanation: the Bradley/Wilder effect. Whatever else happened, it wasn't that white voters said one thing and did another. And make no mistake, this is a hugely important finding, one that should be broadcast far and wide by Obama's people, particularly in South Carolina.
But back to the question at hand. Following up on Prof. Franklin's analysis, Mark Blumenthal examines 8 potential explanations for what went wrong. It's a quick first pass, but its nevertheless worth reading if you're interested in getting some hard data.


