Earlier today, after a USA Today/Gallup poll of swing state likely voters found Mitt Romney four points ahead, the Obama campaign accused Gallup of having an error-prone likely voter model. Gallup editor-in-chief Frank Newport issued this statement in response:
There is no evidence from the last two presidential elections that the likely voter model was disproportionately Republican in its effect compared to the outcome. Gallup’s likely voter model predicted a slightly more Democratic outcome than the actual result in the 2008 and 2004 presidential elections (i.e., predicted Obama winning by a slightly larger margin than he won by, and predicted Bush winning by a slightly lower margin than he won by). In both presidential elections the likely voter model was more predictive than the registered voter model.