Polls show Biden ahead, but after 2016, should we believe them?
Sen. Kamala Harris swiftly reclaimed her time when Vice President Mike Pence interrupted her at the vice presidential debate. USA TODAY
It seems as if there is a new presidential poll released every day — with similar results.
Democrat Joe Biden dominating in Pennsylvania. Now leading Iowa. He even leads in the notoriously tight race of Florida.
Just days after the news of President Donald Trump's COVID-19 diagnosis and subsequent hospitalization, national and state polls continue to show Biden ahead in the presidential race.
In some cases, Biden leads by double digits.
Four years ago, almost to the day, many of the same polls showed Democrat Hillary Clinton well ahead.
Yet Trump won.
So, should the polls be trusted this time around?
Pollsters and political scientists say the 2016 election changed the methodology of how polls are conducted. There is a new emphasis on voters' education levels.
It’s also clear, these experts say, that there are significantly fewer undecided voters than in 2016.
Four years ago, many voters apparently changed their minds in the last 10 days of the campaign — a time when pollsters weren’t in the field.
The experts caution that polls should be viewed as a snapshot in time. Predictions by political pundits helped create the assumption that Clinton would defeat Trump.
“Pollsters are well aware that they were off,” said Terry Madonna, a pollster and political analyst at Franklin & Marshall College in Lancaster, Pennsylvania. “Since 2016, pollsters have been reevaluating many aspects of their polling."
Not all of the polls in 2016 were inaccurate, said David Redlawsk, chair of the University of Delaware's political science department.
Redlawsk, who served as director of polling at Rutgers University for years, noted that many of the 2016 national polls estimated that Clinton had a 3 percentage point lead.
She ended up winning the popular vote by 2 points.
There’s also been a major difference in how Clinton and Biden have performed in these polls, the professor said. Although Clinton had a slight lead, it was dissipating in the days leading up in the election. Polls now show Biden's lead growing.
At times, Trump led the former secretary of state in the polls. Biden, on the other hand, has trailed Trump only twice among the hundreds of national polls conducted in the past year, Redlawsk said.
Winning the national vote doesn’t mean winning the Electoral College.
Also, one of the key lessons from 2016, Redlawsk said, was the importance of adjusting for education in polls.
“The sense now is that polls should have taken a closer look at how they were thinking about education levels,” Redlawsk said. “The reason was it didn’t matter in the past. There weren’t gaps between non-college and college white voters.”
In many cases, white, college-educated voters supported Clinton while white voters with a high school level education level or less voted for Trump.
A FIGHT FOR SCOTUS: Delaware senator says he won't question Supreme Court pick on her religion
Just after the 2016 election, a report by the American Association for Public Opinion Research found that the polls "clearly underestimated Trump’s support in the Upper Midwest."
The researchers attributed this to a significant change in voter preference in the final days of the campaign as well as polls not adjusting for an overrepresentation of college graduates participating in these polls.
Madonna, the Pennsylvania pollster, anecdotally found that many Trump supporters did not tell pollsters they planned to vote for the reality star and businessman. This was a finding confirmed by the American Association for Public Opinion Research’s report.
Unlike in 2016, there are few undecided voters this year, likely only about 10%, Madonna said. He found that many voters in 2016, particularly in Pennsylvania, made up their minds just before the election.
This is known as the “Comey effect.” FBI Director James Comey sent a letter to Congress on Oct. 28 explaining that the agency planned to review more of the personal emails Clinton sent as secretary of state.
This dominated the news cycle, and may have swayed voters.
Many pollsters, including Madonna, were not in the field to capture this change, which is one reason some polls predicted Clinton winning.
It’s important, experts say, to not put too much weight on a single poll, instead of focusing on the overarching trends of what the polls are showing. While Biden is clearly leading in the polls, Trump might still have a shot at winning the Electoral College.
A 95% probability does not mean certainty, cautioned Redlawsk, the UD professor.
“I think we obsess too much about polling,” he said. “The voters are ultimately going to make the decisions they make.”
Contact Meredith Newman at (302) 324-2386 or at email@example.com. Follow her on Twitter at @merenewman.