From Vox: Study: Republicans are embarrassed to admit how much they like Donald Trump

The final section in class covers public opinion polls and touches on - insufficiently at the moment - the problems that public opinion poling faces in a changing technological landscape. Telephone based polling was developed during the day of land-lines and has not made the transition to cell phone dominance very well. The novelty of polling has also worm off, so fewer people are participating when the opportunity arises. This has an impact on polling results because the samples that are drawn no longer - necessarily - reflect the nature of the populations they attempt to measure.

Polls are less and less accurate as a result.

Add to this the problems of taking a poll from an actual person as opposed to a computer. Pollsters are finding out that enough people are worried about being judged by the person giving the poll that it can distort results. They might not give their true opinions to a person.

- For more, click here for the Bradley Effect.

Apparently, something along these lines is happening with support for Donald Trump. Computer generated polls are showing more support than person to person polls. As high as Trump's numbers are, they might be higher.

- Click here for the story.

The most likely explanation for this chasm in levels of support is a concept in social psychology known as "social desirability bias." 

"Social desirability bias Is this tendency for survey respondents to provide answers that lead interviewers to hold a more favorable view of them," said Kyle Dropp, a co-founder at Morning Consult and the study’s main author.

This tendency to lie to pollsters is present all over the place. People, for example, severely under report their involvement in taboo activities such as using illegal drugs or masturbating. And the phenomenon works in the opposite direction: People are more likely to tell callers they have donated to charity, for example, than they actually are to donate.

In politics, the idea of social desirability bias first gained notoriety in the early '80s, when longtime Los Angeles Mayor Tom Bradley, one of the most prominent black politicians in the country, ran as a Democrat in the California governor’s race. Though polls projected his victory by a significant margin, he lost narrowly to the Republican candidate, a white man.

Several years later, Douglas Wilder successfully ran for governor in Virginia, becoming the first black governor to hold office since Reconstruction.
Wilder won his 1989 race by a half-point margin, but opinion polling in the months leading up to the election consistently showed him leading his white opponent by as many as 9 percentage points.

After the fact, political scientists discovered that in both races many white voters told pollsters they planned to vote for the nonwhite candidate but ended up voting against him. This became known as the "Bradley effect" (or sometimes "Wilder effect"): Voters voiced false support for the nonwhite candidate to avoid opening themselves up to criticisms that they were racist.