Primary polls and prediction markets experienced major misses during recent Democratic contests in Wisconsin and Michigan. In Wisconsin, Milwaukee County Executive David Crowley defeated state Rep. Francesca Hong, mirroring a narrow victory by progressive Abdul El-Sayed in Michigan’s Senate primary.
The limits of primary polling and prediction markets faced intense scrutiny following two consecutive surprise outcomes in closely contested Democratic primaries. On Tuesday in Wisconsin, Milwaukee County Executive David Crowley narrowly defeated state Rep. Francesca Hong, a democratic socialist who had led Crowley by more than 20 points in the final update to the Decision Desk HQ polling average.
That dramatic reversal came just a week after a similar polling miss in Michigan. In that contest, left-wing candidate Abdul El-Sayed held on to defeat his more moderate rival, Rep. Haley Stevens, by less than a percentage point in a primary to determine the Democratic nominee for a critical Senate seat. Polls had previously shown El-Sayed ahead by an average of 13 points.
Prediction Markets and Polling Discrepancies in Wisconsin
Prediction markets also struggled to gauge the Wisconsin electorate. Platforms portrayed a race that looked much more secure for Hong than the reality on election day. On Kalshi, Hong held a 95% chance of winning as of Monday night, while Crowley registered at less than 5%. Polymarket described Hong as a “near-lock” with 96% odds before deleting the post internally for its language.
Polling experts noted that primary projection is inherently difficult because determining turnout among specific voters is much tougher than in a general election. Geoffrey Skelley, the chief elections analyst for Decision Desk HQ, pointed out that candidates jumping in and out of races added unique volatility. In Wisconsin, Crowley cycled in and out of the race before returning, while in Michigan, state Sen. Mallory McMorrow dropped out of the primary yet remained on the ballot to win 4 percent of the vote.
“Just the fact that you had candidates getting in and out of the race — or really out of the race, and then also David Crowley getting back into the race — there was just a lot happening and a pretty short amount of time in this race.”
Geoffrey Skelley, chief elections analyst for DDHQ
Open Primaries, Late Deciders, and Electorate Shifts
Analysts highlighted several structural and political dynamics that skewed final numbers. Wisconsin is an open primary state that does not require voter registration by political party, allowing any registered voter to participate. Chaz Nuttycombe, executive director of State Navigate, estimated that as many as one in 10 voters in the Democratic primary were Republicans who chose to cross over.
Nuttycombe explained that because Republicans lacked a competitive gubernatorial primary due to Rep. Tom Tiffany being all but assured the GOP nomination, right-wing voters targeted Hong in the closing stretch. At the same time, undecided voters broke decisively for Crowley as Hong faced intense scrutiny over electability and past social media remarks, including a post about canceling Thanksgiving.
Kyle Kondik, managing editor of Sabato’s Crystal Ball at the University of Virginia’s Center for Politics, suggested that white progressives may have responded to polls at a higher rate than other Democrats. Kondik also noted that El-Sayed’s narrow victory in Michigan and subsequent debates over electability likely contributed to a late surge toward Crowley.
“Hong also expanded her national profile down the stretch of the campaign, and her media appearances did little to dispel the notion that she would have been a very risky nominee for Democrats.”
Kyle Kondik, managing editor of Sabato’s Crystal Ball at the University of Virginia’s Center for Politics
Michigan Senate Race Dynamics and Voter Conventional Wisdom
The polling errors in Wisconsin coincided with debates in Michigan over which faction of the party holds the best chance to flip or hold competitive seats in November. The Michigan primary emerged as a proxy battle between party establishment figures and progressive wings vying to succeed retiring Democratic Senator Gary Peters.
Establishment leaders backed Stevens, pointing to her past success in flipping a GOP-held House seat in 2018 and her broad appeal to independents and moderate swing voters. Meanwhile, El-Sayed built a progressive coalition backed by national figures including Senator Bernie Sanders, Representative Alexandria Ocasio-Cortez, and the United Auto Workers.
Whitt Kilburn, a political science professor at Grand Valley State University, noted that conventional assumptions regarding voter behavior in the state no longer apply.
“Who a ‘likely Democratic primary voter’ is, who will turnout in November, or what policies count as electable, these questions are all less settled than usual in Michigan.”
Whitt Kilburn, political science professor at Grand Valley State University
The winner of the Michigan primary will face Republican Mike Rogers in November for the open Senate seat rated as a toss-up by The Cook Political Report.
