How accurate are election polls?
Critical Analysis
Find answers to the following questions using the visual above, any links below, your big brain, and your knowledge of American government and politics:
Confidence in U.S. public opinion polling was shaken by errors in 2016 and 2020. In both years’ general elections, many polls underestimated the strength of Republican candidates, especially Donald Trump. According to the data in the visual above, in the 2020 election, by how much did public opinion polls overestimate Biden’s 2020 margin of victory over Trump?
Polls are used for all kinds of purposes in addition to showing who’s ahead and who’s behind in a campaign. Fair or not, however, the accuracy of election polling is usually judged by how closely the polls matched the outcome of the election. Describe the historical accuracy of polls in presidential elections since 1936.
The polls in the visual above were estimates of the national popular vote. Describe the aspect of American presidential elections that would allow polls to get the outcome of the national popular vote right and still get the outcome of the presidential election wrong.
In recent elections, most polling organizations conducted polling primarily by telephone. How do you polling people only by phone contributed to pollsters getting the results so wrong?*
Today many prominent polling organizations are beginning to use online methods, or some combination of online, mail and telephone. The result is that polling methodologies are far more diverse now than in the past. How do you think this will make polling more accurate this time around?
Compared with other elections in the past 20 years, polls have been less accurate when Donald Trump is on the ballot. One reason for this overestimation is that Republicans in the Trump era have become a little less likely than Democrats to participate in polls. Pollsters call this “partisan nonresponse bias.” Trump is once again running for office. Do you think that this year’s polls will once again turn out to be wrong?
Polls conducted in the last two weeks before the 2020 election suggested that Biden’s margin over Trump was nearly twice as large as it ended up being in the final national vote tally. Then again, the 2022 midterms saw generally accurate polling. In fact, FiveThirtyEight found that “polls were more accurate in 2022 than in any cycle since at least 1998, with almost no bias toward either party.” Today, in 2024, different polls have different numbers, but when you crunch the polling average Kamala Harris us up by roughly 3 points in national polls. Do you think that margin will be enough for her to win the election?
Because pollsters cannot contact every potential voter they use samples of voting population. All good polling relies on statistical adjustment called “weighting,” which makes sure that the survey sample aligns with the broader population on key characteristics like age, race and gender. For example, pollsters have to take into account that some groups of people – such as older adults and college graduates – are more likely to take surveys. My student Sam said, “I don’t trust polls at all.” Respond to Sam with your own claim about the value and accuracy of polling.
Restoring people’s confidence in polling is an important goal, because robust and independent public polling has a critical role to play in a democratic society. It gathers and publishes information about the well-being of the public and about citizens’ views on major issues. And it provides an important counterweight to people in power, or those seeking power, when they make claims about “what the people want.” Despite the fact that recent presidential election polls have not been perfect, what would life be like without any polls?
In Federalist No. 51, James “Shawty” Madison warned that “ambition must be made to counteract ambition.” Do you think that either the he legislative branch (535 people in U.S. Congress) or the judicial branch (890 authorized Article III judgeships: nine on the Supreme Court, 179 on the courts of appeals, 677 for the US District Courts (includes territorial courts), 16 on the US Court of Federal Claims* and nine on the Court of International Trade.) are ambitious enough to counter the ambition of the president (1 person at top of executive branch)?
Write and Discuss
Take ten minutes to write about the question at the top of the page and then discuss with your classmates.
Act on your Learning
Find a person who needs a ride to vote on election day or an absentee ballot and help them vote.
Get Creative
Make your own poll about the presidential election and share your results with your classmates.
Learning Extension *
Warning, NPR Planet Money Story - parental discretion advised.
