“Large numbers of surveys would be expected to show a wider variety of opinion, even in a close election, due to the randomness inherent in polling,” The Guardian reports.
Josh Clinton and John Lapinski: “The fact that so many polls are reporting the exact same margins and results raises a troubling possibility: that some pollsters are making adjustments in such similar ways that those choices are causing the results to bunch together, creating a potential illusion of certainty — or that some pollsters are even looking to others’ results to guide their own (i.e., ‘herding’).”
“If so, the artificial similarity of polls may be creating a false impression that may not play out on Election Day. We could well be in for a very close election. But there’s also a significant chance one candidate or the other could sweep every swing state and win the presidency somewhat comfortably, at least compared to the evenly balanced picture in the polls.”
Nate Silver: “There’s more herding in swing state polls than at a sheep farm in the Scottish Highlands.”
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