The polls: Why so wrong—again?

“Professional pollsters blew it again,” said Matthew Rozsa in Salon.com. Just as they did in 2016, the polls underestimated President Trump’s strength as they predicted an easy victory for the Democratic nominee. Some polls had Joe Biden ahead by as many as 10 percentage points nationally, while the final margin will probably be a much slimmer 4 to 5 points. On the state level, pollsters predicted a 3- to 6-point Biden victory in Florida and a toss-up in Texas. Trump took Florida by 3-plus and Texas by almost 6. Ohio and Iowa were rated toss-ups, and Trump took both by 8-plus. “Down ballot, the polling performance appeared even worse,” said Steven Shepard in Politico.com. Pollsters predicted a blue wave would carry Democrats to a gain of about a dozen House seats and three to six in the Senate. Instead, Democrats lost House seats and could end up gaining only one in the Senate, depending on the results of two runoff elections in Georgia. Maine Sen. Susan Collins—deemed a potential loser—wound up winning by almost 9 points.

What a “black eye” for polling, said Aaron Zitner in The Wall Street Journal. After 2016, pollsters tried to capture more potential Trump supporters by weighting for rural voters and those without four-year college degrees. But the correction may have been “insufficient” and failed to compensate for the deep distrust many conservatives feel for the mainstream media and polling outlets. They may be hanging up on polling calls “in disproportionate numbers.” Polling “clearly has some serious challenges,” said Nate Cohn in The New York Times. Statistical analysis works only if you can reach “representative” samples of different voting groups. But if some groups decline to participate, polls will be consistently wrong.

If that’s the case, polling faces an “existential” threat, said David Graham in TheAtlantic.com. But the damage won’t be limited to polling companies, which do much more than predict the outcome of elections. “Much of American democracy depends on being able to understand what our fellow citizens think” on such issues as gun control, religious belief, racial justice, climate change, and abortion. Officials use polls to help decide policy, and candidates to craft campaigns. “As Americans sort themselves into ideological bubbles,” the need for reliable polling “is arguably greater now than ever before.” If everyone decides polls can’t be trusted anymore, “we’re all flying blind.”