Hong’s loss in WI raises questions about reliability of primary polls

The unexpected defeat of Francesca Hong in the Wisconsin gubernatorial Democratic primary has cast doubt on the accuracy of primary election polls. Donald Trump has criticized recent polls showing his low approval ratings as fake news, but the disparity between poll results and actual election outcomes in Midwest state primaries could prompt doubts about the reliability of such surveys.

Political analysts suggest that Hong's core supporters may have been overrepresented in polls, while younger voters and progressive individuals who strongly backed her might have been more inclined to participate in polls than their share of the electorate would warrant. Chaz Nuttycombe, head of State Navigate, noted that Hong's supporters were more likely to take part in polls than other voters, citing "non-response bias."

First and foremost, it is likely that Hong's supporters were overrepresented in polls due to their higher response rate. The polling organization State Navigate attempted to correct this error by adjusting the proportion of young voters in their survey, but even with this modification, the poll still showed Hong leading by a significant margin.

Another possibility is that the polls underestimated the Republican-leaning share of voters, as Wisconsin does not require voters to register with a specific party, making it challenging to predict the participation of independents or Republican-leaning voters. Charles Franklin, director of the Marquette Law School Poll, pointed out that after Crowley's late surge, many undecided voters switched their support to him.

In the end, Hong secured approximately 39% of the vote, aligning closely with many poll predictions. However, Crowley, who had just 7% support in the Marquette poll, experienced a surge, climbing to the 20% range in subsequent surveys and ultimately securing 39% of the vote by the time of the primary. The race remained fluid until the final moments of the election. Crowley suspended his campaign on July 8 but later resumed it, while Lt. Governor Sara Rodriguez and her predecessor Mandela Barnes withdrew.

This situation mirrors the outcome of the Democratic Senate primary in Michigan a week earlier, where progressive candidate Abdul El-Sayed led in the polls but only narrowly won by 1 percentage point. The Wisconsin and Michigan results suggest that while progressive candidates' passionate support base is accurately reflected in polls, this enthusiasm does not always translate into higher voter turnout.

The polling errors in both Midwest states underscore the challenges facing primary polls ahead of the 2028 presidential election. Ensuring an accurate assessment of the gap between committed supporters and undecided voters, as well as understanding the behavior of those who delay their decisions until the last minute, is crucial for improving the reliability of such surveys.