There are pundits on both sides of ideological spectrum that believe (or want to be believe) that the polls showing Donald Trump’s unfaltering lead among GOP presidential candidates are wrong.
In early December, U.S. News and World Report claimed that a CNN/ORC poll favoring Trump was guilty of “bad polling practice[s] … that can skew the results.” Similar charges were leveled at pollsters by the website Grist, which argued that it was too early in the campaign season for polling data to be considered n accurate reflection of voter sensibilities.
Now the results of a study have been published that suggests the naysayers were right to doubt the polls. Unfortunately for them, the study indicates that the polls may actually be understating support for the controversial candidate.
The analysis, by Morning Consult, a polling and market research company, looked at an odd occurrence that has cropped up repeatedly this year: Trump generally does better in online polls than in surveys done by phone.
Morning Consult ran an experiment: It polled 2,397 potential Republican voters earlier this month using three different methods — a traditional telephone survey with live interviewers calling landlines and cellphones, an online survey and an interactive dialing technique that calls people by telephone and asks them to respond to recorded questions by hitting buttons on their phone.
By randomly assigning people to the three different approaches and running all at the same time, they hoped to eliminate factors that might cause results to vary from one poll to another.
The experiment confirmed that “voters are about six points more likely to support Trump when they’re taking the poll online then when they’re talking to a live interviewer,” said Morning Consult’s polling director, Kyle Dropp.
“People are slightly less likely to say that they support him when they’re talking to a live human” than when they are in the “anonymous environment” of an online survey, Dropp said.
The most telling part of the experiment, however, was that not all types of people responded the same way. Among blue-collar Republicans, who have formed the core of Trump’s support, the polls were about the same regardless of method. But among college-educated Republicans, a bigger difference appeared, with Trump scoring 9 points better in the online poll.
Social-desirability bias — the well-known tendency of people to hesitate to confess certain unpopular views to a pollster — provides the most likely explanation for that education gap, Dropp and his colleagues believe.
Whether Trump will in fact go on to win the Republican nomination, much less the election, only time will tell. In the meantime, my suggestion is to take the polls — and their critics — with a grain of salt.