Pollsters missed again in Wisconsin. Here's why.

Polls underestimated Crowley’s support in Wisconsin Democratic gubernatorial primary

Two polls conducted in early August showed state Assembly member Francesca Hong leading Milwaukee County Executive David Crowley by roughly 20 points in the Democratic primary for Wisconsin governor. Crowley instead won the August 11 primary by 0.5 percentage points.

Hong received approximately 39 percent of the vote. The final public polls had placed her in the low 40s. Crowley’s support rose from around 20 percent in earlier surveys to roughly 40 percent in the closing days. A similar pattern occurred in Michigan’s Democratic Senate primary the prior week, where polls had overstated Abdul El-Sayed’s margin by double digits; he won by 1 point.

Polling organizations face documented challenges when measuring voter preferences in the final week of a primary. Response rates have declined over the past decade, and weighting models rely on assumptions about turnout that can shift quickly. In open primaries, where any registered voter may participate regardless of party registration, estimating the composition of the electorate is more difficult because historical voting patterns provide less guidance. Former Obama strategist David Axelrod noted that many surveys were completed too early to register late movement.

The final month of the Wisconsin race included several candidate withdrawals linked to scandals and Crowley’s own brief exit followed by re-entry. Hong did not air television advertisements in the closing stretch. Former Obama adviser Dan Pfeiffer stated that the absence of paid media left voters without a counter-message to attacks on Hong’s record. Data from past open primaries show that late-deciding voters often respond to the volume and timing of paid communication when information about candidates is uneven.

Chaz Nuttycombe of State Navigate, whose early August poll showed Hong ahead by double digits, observed that Wisconsin’s open primary rules allow participation by voters who typically cast ballots in Republican contests. His firm’s final poll recorded unusually high traffic from Wisconsin IP addresses in the days before the vote. Pollsters have long reported that open-primary modeling requires additional assumptions about crossover participation, which can vary by contest competitiveness and media coverage.

Axelrod described polling as “a snapshot in time” that can miss rapid changes driven by candidate activity and paid messaging. Crowley campaigned alongside Democratic Gov. Tony Evers in the final week. Some attendees at Hong events told reporters they remained undecided as the primary neared.

Primary polling accuracy has varied in recent cycles. National studies by the American Association for Public Opinion Research have found larger average errors in primaries than in general elections, partly because turnout models must account for variable participation rates across demographic and partisan groups. In this race, the combination of an open primary, limited paid advertising by one candidate, and documented late shifts in preference produced the observed discrepancy between pre-election surveys and the certified result.