By Michael Barone, September 29, 2012 –
As a recovering pollster (I worked for Democratic pollster Peter Hart from 1974 to 1981), let me weigh in on the controversy over whether the polls are accurate. Many conservatives are claiming that multiple polls have overly Democratic samples, and some charge that media pollsters are trying to discourage Republican voters.
First, some points about the limits of polls. Random-sample polling is an imprecise instrument. There’s an error margin of 3 or 4 percent and polling theory tells us that one out of 20 polls is wrong, with results outside the margin of error. Sometimes it’s easy to spot such an outlier; sometimes not.
In addition, it’s getting much harder for pollsters to get people to respond to interviews. The Pew Research Center reports that it’s getting only 9 percent of the people it contacts to respond to its questions. That’s compared with 36 percent in 1997.