Before elections, there's always a lot of fussing about whether the polls are accurate, and how they might be misrepresenting the situation. Afterwards, when all the data is available, the election is over and nobody really cares what the polls said. But in deference to my past self who was obsessing over the polls, I'm looking at this summary of how each pollster did on the Senate races they covered. The following numbers represent the extent to which each pollster overestimated Republican performance on average, and the average error. As it turns out, each pollster generally overestimated Republican performance.
Rasmussen: 2.15% GOP overestimation, 3.23% average error
Mason-Dixon: 3.73% GOP overestimation, 3.73% average error
Reuters/Zogby: 1.67% GOP overestimation, 4.56% average error
Zogby Battlegrounds: 5.36% GOP overestimation, 6.45% average error
SurveyUSA: 2.55% GOP overestimation, 5.22% average error
Quinnipiac: 3.67% GOP overestimation, 3.67% average error (only 3 polls)
