All the conservative criticism of the election polls last year emphasized the belief that Republicans were being under-sampled in the polls. Had that been true, Romney’s popular vote percentage should have been higher than his poll percentage, which was a mathematical possibility even despite his popular vote loss. So how do the numbers work out? Here’s a selection of the final pre-election results from 7 prominent polls.
That’s not so good for the under-counting Republicans hypothesis. Romney came in pretty much right on target, while Obama actually increased a bit. Both are within the margin of error, but keep in mind that the margin of error is a bell-shaped curve, so the Romney “miss” of .8% is a much more likely than the Obama miss of 2.5%.
This doesn’t indicate a Democratic undersampling by the polls, though. The more plausible interpretation is that late-breaking independents went Democratic more than Republican. But it does indicate that the Republican undersampling hypothesis wasn’t just over-stated; it was dead wrong, 100% absolutely positively indisputably wrong. And for all the hand-wring, all the wailing and gnashing of teeth, and all the actual real-for-sure legitimate qualms about the weaknesses of survey research as a methodology, for predicting election outcomes the polls–at least the average of the polls–has consistently proven itself to be pretty damned good.