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 to 36 percent in 1997.
Interestingly, response rates are much higher in new democracies. Americans, particularly in target states, may be getting poll fatigue. When a phone rings in New Hampshire, it might well be a pollster calling.
Are those 9 percent representative of the larger population? As that percentage declines, it seems increasingly possible that the sample is unrepresentative of the much larger voting public. One thing a poll can’t tell us is the opinion of people who refuse to be polled.