After the 2020 presidential election, the political world is debating a familiar question from 2016: What went wrong with polls in key states?
One poll that hit its marks was the Star Tribune/MPR News/KARE 11 Minnesota Poll, conducted by Mason-Dixon Polling & Strategy. The last survey from September found Joe Biden leading President Donald Trump by 6 percentage points in Minnesota, and U.S. Sen. Tina Smith leading Jason Lewis by 8 points. Both were within the poll's 3.5% margin of sampling error.
We asked Mason-Dixon CEO Brad Coker to share his thoughts on polling.
Many pollsters again overestimated Democratic strength in key swing states in 2020. What do you think went wrong?
As in 2016, pollsters were unable to capture a specific group of voters — what has come to be referred to as "shy Trump voters."
So who are they?
Identifying the shy Trump voter was not difficult. In the final stretch of the 2016 presidential election, two major news organizations released nationwide polls that indicated Hillary Clinton was ahead of Donald Trump by 25 to 32 percentage points among college-educated white women. The Election Day exit poll, conducted by a consortium that included these two organizations, indicated that Clinton only carried this group by 6 points (51 to 45%). This 20-plus percentage point discrepancy was the largest underrepresentation of the Trump vote in 2016.
Fast-forwarding, I am aware of at least one national poll that indicated Biden's lead over Trump among college-educated white women was 27 points. Although exit poll results are not completely reliable given the number of mail-in voters this cycle, the estimates I have seen suggest the actual margin was in the 10 to 15% range. History seems to have repeated itself.
Have you encountered this "shy voter" phenomenon in other elections?
I first encountered it in the 1980s when conducting polls in North Carolina that included Republican Sen. Jesse Helms — a very controversial politician of the time. Using proven methods that produced accurate results for every other race on the state ballot, we repeatedly underestimated Helms' support by about 5 to 7%.
What surprised you most this election cycle?
Only one outcome truly surprised me in 2020 and that was the U.S. Senate race in Maine. Every published poll showed Democratic challenger Sarah Gideon leading incumbent Republican Susan Collins, with the average lead at 6 points. Collins ended up winning by 9 points. The magnitude of this group inaccuracy is troubling.
What one thing do you wish the public understood better about polling?
That poll results cannot predict the future, but can only measure what is going on at the time the poll is taken.