Ahead of the November 8 presidential vote, nearly all pollsters were convinced Hillary Clinton would win.
To borrow a phrase from US president-elect Donald Trump, the pollsters were wrong, "big league".
Ahead of the November 8 presidential vote, the Republican candidate
was some four percentage points behind his Democratic rival, Hillary
Clinton, according to the
last pre-election poll by Fox News, a right-leaning network, and others.
The RealClearPolitics website, which aggregates polls, consistently put Clinton ahead of the businessman.
The FiveThirtyEight site
of Nate Silver, a venerated pollster, gave Clinton a 71.4 percent
chance of sauntering back into the White House in January 2017.
The New York Times’s Upshot gave Trump even worse odds on becoming the 45th president.
But, reminiscent of Britain’s Brexit vote in June and Colombia’s
peace-deal snub in October, Americans had other plans with many more
voters backing the anti-establishment candidate than pollsters foresaw.
Trump had secured momentous upset victories in Florida, North
Carolina, Pennsylvania and Wisconsin - critical battleground states
where most public polls and private projections had put Clinton ahead.
As analysts probed what a Trump presidency means for the world
economy, trade deals, immigration and even the war in Syria, number
crunchers went back to their spreadsheets to assess where the data
models went wrong.
'Brexit effect'
"There was indeed a Brexit effect," Allan Rivlin from Zen Political Research, a consultancy, told Al Jazeera.
"There were un-modelled Trump voters. If you had asked them, they
would have happily told you they were supporting Trump. But nobody asked
them because they weren't in the model because they hadn't voted in
recent elections."
Pollsters survey for two basic variables - the demographic make-up of voters, and how each sub-group is expected to ballot.
Some groups, such as young black men, are less likely to vote than
others, such as old white women. Pollsters attach different weight to
various categories and, according to Rivlin, they under-valued whites
who had not voted in recent elections.
Trump's surprise victories were in states with declining industries,
like Pennsylvania and Wisconsin, where pollsters underestimated how many
disaffected whites would vote because of their track record in skipping
polling days, he added.
"There were more Republican voters in the key states and Republicans
did a better job of identifying those key states," Rivlin said.
"There was a failure of imagination on the part of the Democrats to
see the anger at Washington and economic discontent among white
working-class voters in the suburbs and exurbs of the Great Lakes
states."
'Hidden' Trump voters
Some analysts point to other "hidden" Trump voters who were
embarrassed to admit support for the truculent property magnate when
speaking with flesh-and-blood pollsters, as opposed to the automated
systems used by some firms.
The Los Angeles Times/University of Southern California
tracking poll
consistently pegged Trump as the leader throughout the final months of
the campaign. Many rival pollsters derided its seemingly out-of-step
forecast.
That poll is based on an internet survey rather than a telephone
questionnaire. It may have been more accurate because online respondents
were more likely to reveal their support for Trump than when speaking
with a human.
This raises other issues about data-collection. Polls vary in many
ways and differ in their sample sizes and whether respondents are
randomly selected from telephone directories or pulled from voter rolls
from previous elections.
Even conducting surveys via mobile phones, as opposed to land lines, can skew results.
"All polls are not equal. They don't use the same methodology. Using
robo-calls as opposed to human beings is faster and easier and you get a
lot more bang for your buck," Peter Brown assistant director of
Quinnipiac University Poll, told Al Jazeera. "Some are better than
others."
Badly-run and misleading polling firms may create false impressions, said Brown.
"Tell me, do you know who these organisations are. Have you heard of
them? Have you dealt with them? Do you know their backgrounds? Are they
part of a political consulting firm that works either for one party or
the other?" asked Brown.
As results came in, FiveThirtyEight's Jody Avirgan spoke of the need
to "piece together what we know about this big, complicated moment in
American history". A postmortem is expected later.
In The New York Times,
media columnist Jim Rutenberg acknowledged that "something was
fundamentally broken in journalism" and probed whether the media had
been too cosy with Clinton's camp.
Popular vote for Clinton
While pollsters got the outcome wrong, they may not have been too far
off, said Matt Barreto, co-founder of polling firm Latino Decisions.
Clinton is still on track to win the popular national vote and secured
big margins in such populous states as California and New York.
Some ballots have yet to be counted, but Clinton's 59.7 million votes
amounted to 48 percent of the popular vote, compared to Trump's 59.5
million (47 percent). In the Electoral College that determines the
winner, however, Trump's 279 votes beats Clinton's 228 current tally.
But Trump turned out a small yet decisive number of "disaffected
white voters in small pockets of a few swing states" like Florida, North
Carolina and Wisconsin that pushed him above the 270 Electoral College
votes needed to win, he added.
"The states that he won, he did not win by a lot," Barreto said.
Trump has his own theories. Ahead of polling day, he said pollsters did a bad job and released
"phony numbers".
In his acceptance speech in the early hours of Wednesday, he praised
the groundswell of popular support that carried him to victory.
"Ours was not a campaign, but rather an incredible and great movement
made up of millions of hard-working men and women who love their
country and want a better, brighter future for themselves and for their
families," he told the crowd in New York.
