Part 3 of 3: Why the differences between new polls from Quinnipiac and the UW Election Research Center?

Editor’s Note: Previously, we asked political writer and Progressive Magazine contributor Jud Lounsbury to explain why he frequently takes issue with the Marquette University Law School poll. What he teaches us about the make-up of the pool of respondents can be used to explain the differences in two other recent polls about presidential candidate preferences in Wisconsin.

A poll released last Friday from Quinnipiac University in New York that showed Trump up handily in Wisconsin was significantly different than its surveys in Michigan and Pennsylvania where Trump trailed all Democrats in head-to-head matchups. In Michigan, all of the Democrats were up 1 to 5 points, and the Pennsylvania Democratic gap was 3 to 8 points over Trump. (Wisconsin went to Trump by less than one point over Hillary Clinton in 2016.) The survey also showed Trump’s approval-disapproval ratings at 50-47 which would be higher than most polls. 

One explanation may be that the Wisconsin sample had a +6 margin of self-identified Republicans to Democrats (32 to 26 percent of the respondent pool) compared to +3 for Michigan and +5 in Pennsylvania. 

The survey released Sunday by the University of Wisconsin Election Research Center (done in partnership with the Wisconsin State Journal) shows the same tight race reflected in every other Wisconsin poll to this point. All of the Democratic candidates are up on Trump, but only by 1 or 2 percentage points, well within the margin of error. And Trump’s approval-disapproval rating of 44-52 is also in line with previous polling. The ERS online survey of 1,000 people in Wisconsin was conducted by the polling and marketing firm YouGov, rather than through telephone conversations.

And while Quinnipiac’s sample was a +6 for Republicans, the ERC sample was +5 for Democrats, 35 vs. 30 percent of the pool.)

Of those respondents likely to vote in April’s Democratic primary, Vermont Sen. Bernie Sanders is well ahead of the field with 30 percent support compared to 13 percent for former Vice President Joe Biden and former New York City mayor Michael Bloomberg, 12 percent for Massachusetts Sen. Elizabeth Warren and former South Bend, Indiana, mayor Pete Buttigieg, 11 percent saying they were unsure, and 9 percent for Minnesota Sen. Amy Klobuchar. 

Political science Professor Larry Burden, director of the UW ERC, said the data –combined with polling done in Pennsylvania and Michigan– reaffirms the importance of candidates, parties and groups moving beyond any traditional base of support.

“Turning out new voters may be an important key to Democratic success this election year. Voters who did not turn out in the 2016 presidential election are especially favorable to Democratic candidates in 2020. Combining the three states, 82% to 89% of those who voted for Clinton in 2016 plan to vote for the Democrat in 2020. A higher share of those who voted for Trump (89% to 93%) plan to vote for him again in 2020. However, respondents who did not vote in 2016 favor each of the Democrats over Trump by double-digit margins.”

Burden said the survey also underscores the ongoing gender gap between the parties.

“Two-thirds of respondents said that America is “ready” to elect a woman president. This belief is widely held among Democrats (80%) and independents (74%), but much less so among Republicans (47%).”

The ERC/YouGov method of online opt-in polling does not escape criticism from Progressive Magazine contributing writer Jud Lounsbury who references a study done by the Pew Research Center that claims such polling contains a small but measurable share of bogus respondents that “introduce a small, systemic bias into estimates like presidential approval.”

From biases to unbalanced samples to methodology, the bottom line is that caveat emptor is a caution that is applied to the marketplace of polling as easily as it applies to the marketplace of goods and services. “Let the Buyer Beware” does not mean “don’t buy,” it means a little homework goes a long way toward understanding that there are plenty of ways to ask voters a question only they can answer with certainty and finality, but not until Election Day.