Even if the Polls Are Really Off, Trump Is Still
in Trouble
Joe Biden’s lead is sufficient to cover a sizable
error. And several of the biggest problems with polling in the last election
have either been addressed or become less relevant.
Nate Cohn
By Nate
Cohn
July 16,
2020
updated
9:05 a.m. ET
With Joe
Biden claiming almost a double-digit lead in national polls, one question still
seems to loom over the race: Can we trust the polls after 2016?
It’s a good
question. But for now, it’s not as important as you might guess. If the
election were held today, Mr. Biden would win the presidency, even if the polls
were exactly as wrong as they were four years ago.
The reason
is simple: His lead is far wider than Hillary Clinton’s was in the final polls,
and large enough to withstand another 2016 polling meltdown.
If polls
were off by as much as they were in 2016, Joe Biden would still lead most
battleground states.
TOTALS
BASED ON CURRENT POLLS* IF POLLS ARE
AS OFF AS THEY WERE IN 2016
Electoral
coll. 390 310
CURRENT
POLLS IF POLLS ARE AS OFF AS
THEY WERE IN 2016
Arizona Biden +3 Biden
<1 o:p="">1>
Florida Biden +6 Biden
+3
Michigan Biden +10 Biden +5
North
Carolina Biden +3 Trump +1
Pennsylvania Biden +7 Biden
+2
Wisconsin Biden +8 Biden <1 o:p="">1>
U.S. avg. Biden +9 Biden +7
2020 poll averages are based on surveys conducted since June 1 and compiled by FiveThirtyEight. Prior years use averages of polls conducted within three weeks of Election Day. Where no qualifying state polling exists, the Electoral College estimates suppose that a state votes as it did in the preceding election.
This is not
to say that President Trump can’t win. There are still nearly four months to go
until the election — more than enough time for the race and the polls to change.
The race changed on several occasions over the final months in 2016. And this
race has already changed significantly in the last four months. According to
FiveThirtyEight, three months ago Mr. Biden held a lead of only about four
points.
And while
Mr. Biden can currently survive a 2016-like polling error, there is no reason a
polling error couldn’t be even larger in 2020.
But for
now, his lead is large enough to survive a 2016 repeat and just about every
general-election polling error in recent memory. He leads by an average of
nearly 10 percentage points in national polls since June 1, well ahead of Mrs.
Clinton’s four-point lead in the final national polls or her peaks of about
seven points in early August and mid-October.
Mr. Biden
also enjoys a far wider lead in the battleground states likeliest to decide the
presidency. His 13-point lead in a Monmouth University poll of Pennsylvania
published on Wednesday, for instance, puts him in a much stronger position than
Mrs. Clinton, who had a four-point lead in the last Monmouth poll of
Pennsylvania taken just before the election.
Of course,
the polls could be even further off this time than four years ago. But there
are also many reasons to think they could be better this time around.
Perhaps
most important, many pollsters now weight their sample to properly represent
voters without a college degree. The failure of many state pollsters to do so
in 2016 is widely considered one of the major reasons the polls underestimated
Mr. Trump’s support. Voters without a four-year college degree are far less
likely to respond to telephone surveys — and far likelier to support Mr. Trump.
By our estimates, weighting by education might move the typical poll by as much
as four points in Mr. Trump’s direction.
Though many
state pollsters still do not weight by education, far more do than four years
ago. The Monmouth poll is one example. The final Monmouth poll of Pennsylvania
in 2016, which showed Mrs. Clinton up four percentage points, would have shown her
with a two-point lead, 47 percent to 45 percent, if it had been weighted by
education, according to Patrick Murray, director of the poll. That alone covers
about half of the difference between the actual result and the final Monmouth
poll, and it’s a reason to have more confidence in the new Monmouth poll.
Education
weighting is not enough to ensure a perfect result. After all, Mrs. Clinton
still would have led — albeit quite narrowly — in the final Monmouth poll of
Pennsylvania, even weighted by education. And other high-quality,
education-weighted state polls, like the Marquette Law School poll in
Wisconsin, still showed Mrs. Clinton with a considerable edge in 2016. Other
factors were clearly at play.
But many of
the other sources of polling error in 2016 also seem less likely to repeat.
There are
far fewer undecided or minor-party voters now than four years ago. These voters
broke in Mr. Trump’s favor, according to exit polls and postelection surveys
that recontacted pre-election respondents, helping to explain part of his
strength in the final results. Undecided voters could again break toward Mr.
Trump, but this time there are simply fewer of them — and therefore less
opportunity for the polls to be wrong for that reason.
Another
component of the polling error in 2016 was turnout. It is hard to generalize
the role of turnout in the polling misfire because there are as many
likely-voter models as there are pollsters. But some pollsters probably
overestimated Black turnout by relying too heavily on Obama-era turnout models.
This time, reliance on the last election could just as easily understate
Democratic turnout. In general, the party out of power tends to enjoy
relatively higher turnout than when it’s in power, and that could help
Democrats compared with 2016.
In the case
of the Monmouth poll, it turns out that turnout was a significant factor. Mr.
Trump would have led Mrs. Clinton by one percentage point, 45 percent to 44
percent, in the final Monmouth University poll of Pennsylvania if it had been
weighted by education and if the likely-voter sample had consisted only of
those who ultimately voted, according to voter file records. (Mr. Trump won the
state by 0.7 of a point.)
Similarly,
the final New York Times/Siena College poll of North Carolina, which was
conducted over the weekend before the election and found the candidates tied,
would have shown Mr. Trump ahead by four percentage points (he won by 3.6
points) if the likely-voter sample had consisted only of validated voters.
These kinds of findings led many pollsters to conclude that survey research
wasn’t fundamentally broken after the 2016 election, and led many to redouble
their efforts rather than abandon the enterprise.
Of course,
addressing the last election’s polling problems doesn’t ensure that there won’t
be another type of polling failure.
Biden’s
lead would be even bigger if we didn’t poll larger numbers of hard-to-find
voters, like voters who haven’t voted in recent elections but may in 2020.
NYT/SIENA
POLL, JUNE 2020 WITH FEWER HARD-TO-FIND
RESPONDENTS
Arizona Biden +7 Biden
+10
Florida Biden +6 Biden
+9
Michigan Biden +11 Biden +14
North
Carolina Biden +9 Biden +9
Pennsylvania Biden +10 Biden
+13
Wisconsin Biden +11 Biden +13
U.S. avg. Biden +14 Biden +13
Based on a
New York Times/Siena College poll of 3,870 registered voters from June 8 to
June 18. The “without hard-to-find voters” estimates suppose the results with
simple random sampling, without stratification, coverage or response rate
adjustment.
Perhaps the
biggest risk is one that has loomed over the polling industry for a decade:
declining response rates to telephone surveys. Up until now, there has been
little evidence that low response rates have endangered the accuracy of
high-quality survey research. It turns out that the people who respond to
telephone surveys appear to vote similarly to people from their same
demographic group who do not respond.
But they
are different in some ways. They are likelier to be volunteers. They are
likelier to express trust in their neighbors and society. Such differences
could become more significant, or grow into closer alignment with political
views. In the worst-case scenario, declining trust in experts, the news media
and polling could lead to systematic nonresponse bias, where even adjusting for
education or demographics would be far from enough to ensure a representative
sample.
There are
reasons to doubt that this will happen. Only a few months ago, polls showed Mr.
Trump highly competitive, and there is a fairly simple explanation for the turn
against him: his handling of coronavirus. The trend against the president holds
regardless of how the survey was conducted. Panel surveys, in which respondents
are repeatedly contacted, also show former Trump supporters abandoning the
president. And most surveys show the right number of respondents who say they
voted for Mr. Trump in 2016. They’re just saying they won’t vote for him again.
It would take an awfully targeted form of bias for polls to get the right
number of 2016 Trump voters yet vastly overrepresent those who are leaving him.
Even so,
you can imagine how it could, possibly, happen — such problems can’t be
discounted. The problems even harder to discount are those that can’t be
imagined.
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