Embarrassing polling flubs seem increasingly common. Going into the Michigan primary, surveys showed Hillary Clinton leading Sen. Bernie Sanders among likely voters by double digits, only to have Sanders pull off a stunning two-point victory on March 8. A similar forecasting failure befell the British elections last year, when pollsters predicted a neck-and-neck race between the Conservative and Labor parties resulting in a divided government, only to have the Conservatives win a simple majority. These are but two examples of a more global trend.
It’s not hard to find precise technical explanations for any given discrepancy between polling forecasts and election day results. But I prefer to think of these blunders as the downstream consequences of large-scale social and technological changes, which affect how the public consumes polls and how pollsters conduct them. CONT.
Rob Santos (Urban Institute), Los Angeles Times