Marquette’s August poll shows a dead heat between Democrat David Crowley and Republican Tom Tiffany, and closer scrutiny suggests the numbers could be worse for Crowley once historical patterns and pocketbook issues are considered.

The new Marquette University Law poll found Crowley and Tiffany essentially tied, with about 12 percent of registered voters still undecided. That undecided bloc makes the race volatile, and it gives Tiffany an opening if he can consolidate his base and peel off skeptical voters. Polls in August tend to be noisy, and that matters when margins are this thin.

Among likely voters the lead tightens to roughly five points for Crowley, a slim cushion that offers little comfort when you account for the poll’s track record. From a Republican perspective, this is encouraging because history suggests Marquette’s August snapshots lean Democrat. If that bias holds, Tiffany’s real position could be stronger than the headlines imply.

The August Marquette pattern is important because seasonal sampling and turnout models can hide late movement toward Republicans in the fall. Given the undecided share, a modest swing could shift the race decisively. Campaigns that read these polls as final results will miscalculate where resources and messages should go.

https://x.com/MULawPoll/status/2092663583079317934

This is good news for Tiffany, and here’s why: the August MU Law poll has a history of overestimating Democratic support. Analysts who track these cycles point to an average Democratic overestimate that matters when margins are small, and that historical tilt must be part of any realistic forecast.

Below is a detailed look at Marquette’s August performance over the years, illustrating why cautious interpretation is warranted.

Since its inception, Marquette’s August poll has not just been wildly unsuccessful at predicting the ultimate result of a November race; it has also overestimated Democrats’ support by an average of 3.5%. Even when taking out the anomalous 2016 presidential election (when every poll right up until Election Day) was enormously wrong, the average overestimation of Democrat support by 2.1%.

Just once did it get a race exactly right in August—its 2024 presidential election poll showing President Trump beating Kamala Harris by a point—and in five of the nine August polls of presidential and gubernatorial races it has conducted over the past decade, it has been off by six or more points. In every single one of those five massive misses, it dramatically overestimated the support of the Democrat.

Just once, in that August 2024 presidential poll, did it ever show the Republican candidate leading even though Republican candidates went on to win their respective races four times in nine elections.

Just three times in nine polls did the August Marquette poll overestimate Republican support: In 2018, when it showed incumbent governor Scott Walker and challenger Tony Evers tied (Evers went on to win the race by a point) and incumbent Senator Tammy Baldwin up three on challenger Leah Vukmir (Baldwin won by 11), and in 2022, when it had Evers leading Republican Tim Michels by two points (Evers won by three).

Beyond methodology, there’s an issue that’s being hammered at the local level: data centers. Political operatives argue that data centers have become a wedge issue, and that Crowley’s past comments about encouraging their spread are politically risky. Voters outside Milwaukee see these projects through a different lens than urban leaders, and that mismatch is politically exploitable.

“Data centers are now the issue in the governor’s race and Republican Tom Tiffany has staked out the position that the overwhelming majority of Wisconsin is on, and David Crowley’s past comments pretty much throughout the primary are positioning him as the guy who wants to bring more data centers to communities that aren’t his. And that’s the critical thing,” O’Donnell said.

“Crowley is from Milwaukee and the rest of Wisconsin always views Milwaukee, rightly or wrongly, with a good bit of suspicion. Yes, it’s the economic engine of the entire state, but it’s also seen as forcing its will on the other 71 counties. The Milwaukee County Executive very publicly earlier this month saying that he wants to ‘share the wealth of data’ centers with the rest of the state’ now that Milwaukee, Madison, and Green Bay already have them, is being interpreted as meaning, ‘Yeah, no, my community of Milwaukee and my favored liberal cities of Madison and Green Bay don’t want or need data centers. But you smaller, Republican, rural, and exurban communities? You need them so that you can be the economic engine of the state in the economy of tomorrow, absorbing all of the negatives of data centers while we in Milwaukee, Madison, and Green Bay generate the revenue in the form of state tax income, while absorbing none of the negatives.'”

“That is a big, big problem.”

That perception sting is real because many Wisconsinites outside Milwaukee already view the county as taking more than it gives, especially on matters of crime and fiscal responsibility. Longstanding grievances about taxes, budgets, and public safety make it easy for opponents to frame Crowley as an insider who mismanaged his own backyard and now wants to export new burdens to other communities.

Crowley’s record as Milwaukee County Executive—higher taxes, budget shortfalls, and persistent crime concerns—creates political vulnerability heading into November. For Republicans, that fact pattern provides a clear argument: leadership that can’t get local finances or public safety right shouldn’t be trusted with statewide power.

With undecideds still in play and Marquette’s August lean toward Democrats taken into account, the race looks far from settled. For Tiffany, the path forward is straightforward: keep the focus on practical issues that hit voters’ wallets and safety, and let the historic polling tilt correct itself as turnout models firm up.