It's fairly clear that no matter what method is utilized, the national polls were too favorable towards Romney. Only eight out of 113 polls (or 7.1%) during the final month had Obama's lead at above 3pt. Three of the eight were from the Rand Corporation, two were from Google, and the rest were scattered between Democracy Corps, IBD/TIPP, and the United Technologies/National Journal survey.The problem with these results were overly restrictive likely voter screens. For example, Gallup had President Barack Obama leading 49-46 among registered voters. Had they stopped there, they'd be sitting pretty with their results. Instead, they decided that brown people and young voters weren't going to turn out, and had Romney winning 49-48 among likely voters.
During the final week, only three out of 30 polls (or 10%) conducted had Obama's lead above 3pt. They belonged to Democracy Corps, Google, and Rand. If Obama's lead climbs to 3.5pt, then, even with rounding, the vast majority of national polls were off in the final week. (Note: usually one would consider a poll giving Obama's victory margin as 3pt to be right if the final result were between 2.50 and 3.49pt.)
There was a consistent 2-4-point difference between registered and likely voter results in most state and national polling, the reason that I predicted a a 3.5-point Obama victory in the national popular vote. (Note, that link compares my predictions to outdated vote totals. My calls will look even better after all votes are counted.)
To be sure, the theory that core Democratic groups wouldn't vote as heavily as 2008 wasn't ludicrous. It is much harder to get our people to turn out, and the polling showed less base intensity this year compared to 2008. Still, early voting gave us an insight into actual voting behavior, and it was clear that we were either meeting or exceeding 2008 turnout. So if our people were voting early in droves in places like North Carolina, Iowa and Ohio, then pollsters who claimed otherwise had to be wrong.
That, and registered voter numbers have historically been more accurate. Past performance may not be a predictor of future results, but layer on top of that the early voting totals, and it was pretty cut and dried to me.
So yes, the polls were skewed toward Romney—but only because of overly restrictive likely voter screens. Had they all stuck with their registered voter results, they would've been golden.
p.s. Just look how crazy Gallup's LV screen is:
Gallup's likely-voter model is a battery of seven questions it uses to determine which respondents are most likely to cast ballots. These questions include how likely they say they are to vote, their self-reported vote history, whether they know where to vote, and how much thought they have given to the election.Compare that to PPP's likely voter screen:
Respondents are awarded points for their answers to these questions, and only those who accrue a significant number of points pass through the likely-voter screen.
If you don't plan to vote in this fall's election, hang up now.