A new report from a group of polling experts confirmed that the 2020 presidential polls were way off the mark. But the study failed to find a definitive answer to the big question: Why?
The report raises concerns that polling for elections in 2022 and 2024 may suffer from the same mistakes.
How wrong did the pollsters get it last year? According to the report from the American Association for Public Opinion Research, public opinion polls for the 2020 presidential election were the most inaccurate in the past 40 years, and state polling was the worst in 20 years.
From The Washington Post:
Public opinion polls in the 2020 presidential election suffered from errors of “unusual magnitude,” the highest in 40 years for surveys estimating the national popular vote and in at least 20 years for state-level polls, according to a study conducted by the American Association for Public Opinion Research (AAPOR).
The AAPOR task force examined 2,858 polls, including 529 national presidential race polls and 1,572 state-level presidential polls. They found that the surveys overstated the margin between President Biden and former president Donald Trump by 3.9 points in the national popular vote and 4.3 percentage points in state polls.
Polls understated the support for Trump in nearly every state and by an average of 3.3 percentage points overall. Polls in Senate and gubernatorial races suffered from the same problem.
According to Josh Clinton, a Vanderbilt University political science professor who led the 19-member task force behind the study, Democratic support was overstated “across the board.”
“It didn’t matter what type of poll you were doing, whether you’re interviewing by phone or Internet or whatever. And it didn’t matter what type of race, whether President Trump was on the ballot or was not on the ballot.”
The mistakes weren’t just for the presidential race. Polling for Senate and Governor’s races showed a similar pattern where the margin for Democratic candidates was overstated versus their Republican opponents.
Unlike in 2016, when polling errors were traced to mostly underestimating the educational divide and Donald Trump’s popularity with voters without college degrees, there is no clear “prime suspect” that the task force can blame for the 2020 mistakes.
This is a concern because without a definitive cause, there is no way to come up with a fix to the methodology for polling ahead of the next elections.
“Identifying conclusively why polls overstated the Democratic-Republican margin relative to the certified vote appears to be impossible with the available data.”
The authors of the new report can only point to possible reasons for the inaccurate polling, with one being that key groups of people simply don’t answer polls.
Decreasing response rates have been a major source of concern for pollsters for more than a decade. But the politicization of polling during the Trump era — including the feedback loop from the former president, who has falsely decried poll results he doesn’t like as “fake” or deliberately aimed at suppressing enthusiasm for answering polls among GOP voters — appears to be skewing the results, with some segment of Republicans refusing to participate in surveys.
