“Over the past four years, experts reached an academic consensus about [2016 state-level] polls’ biggest flaw: a failure by many to ‘weight for education.’ ‘Weighting for education’ is an attempt to compensate for the fact that college-educated people are both more likely to respond to polls and more likely to be Democrats. A poll that’s weighted for education takes responses from people without college degrees and gives them more ‘weight,’ so the poll more accurately represents the demographics of the place it’s trying to survey.”

“For example, here’s how a Wisconsin poll that’s weighted for education would play out: Pollsters call thousands of people, but many don’t answer their phones. Of those who do answer and take the survey, 60 percent have a college degree. But here’s the problem: only about 30 percent of Wisconsin’s population has a college degree, according to the U.S. Census. If the poll published those results without any adjustments, it would disproportionately represent the opinions of college-educated voters, who tend to be more liberal than their neighbors without college educations. So, the poll takes the responses from the people without college degrees and gives them more ‘weight,’ until the demographic ratios in the poll align with the demographics of the state. According to Ashley Kirzinger, associate director of public opinion and survey research at the Kaiser Family Foundation and a member of the American Association for Public Opinion Research’s poll transparency project, a number of state-level polls didn’t weight for education in 2016. But she said many have now course-corrected. ‘If polls get it wrong this year, it’s not going to be because they weren’t weighting for education'” – Wisconsin Public Radio.