Most preelection polls in 2020 overstated Joe Biden’s lead over Donald Trump in the national vote for president, and in some states incorrectly indicated that Biden would likely win or that the race would be close when it was not. These problems led some commentators to argue that “polling is irrevocably broken,” that pollsters should be ignored, or that “the polling industry is a wreck, and should be blown up.”
The true picture of preelection polling’s performance is more nuanced than depicted by some of the early broad-brush postmortems, but it is clear that Trump’s strength was not fully accounted for in many, if not most, polls. Election polling, however, is just one application of public opinion polling, though obviously a prominent one. Pollsters often point to successes in forecasting elections as a reason to trust polling as a whole. But what is the relevance of election polling’s problems in 2020 for the rest of what public opinion polling attempts to do? Given the errors in 2016 and 2020, how much should we trust polls that attempt to measure opinions on issues? CONTINUED
Scott Keeter, Nick Hatley, Arnold Lau & Courtney Kennedy, Pew Research Center