Wisconsin votes a lot. I mean that in two ways: voter turnout is often high and opportunities to vote arrive frequently. In 2024, the state’s voter turnout was the highest in the nation (76.66% of eligible voters). And statewide elections occur almost every year, often more than once. The total number of voters participating in these contests routinely varies by millions, with inescapable consequences for the parties. With maximum turnout, Republicans enjoy a slight edge, but Democrats have opened a seemingly insurmountable advantage in lower-turnout contests.

For the purposes of this analysis, I’m interested in statewide elections when Democrats, or Democratic-endorsed nonpartisan candidates, ran against Republicans, or their endorsees. This includes November general elections, April elections for State Supreme Court Justice or State Superintendent, and February primaries for those same offices. Unlike in partisan primaries, when Democrats and Republicans vote in separate contests, nonpartisan Wisconsin primaries occur only when at least three candidates are on the ballot, and the top two vote-getters both advance to the April general.

These days, the nonpartisan status of statewide April (and February) elections is just a formality. The parties endorse and fund their preferred candidates, and the voters are well aware of even these unofficial candidate affiliations. The correlation between the vote for Wisconsin Supreme Court Justice and the previous presidential election grew from 0.002 in 1978 to 0.99 by 2025.

Since 2020, there have been 11 statewide elections pitting Democrats against Republicans, counting formally nonpartisan races in which the party affiliation of the candidates was clear.

Those elections ranged in turnout from 3.4 million in the November 2024 presidential election to 326 thousand during the February 2021 primary for State Superintendent.

At the Marquette Law School Poll, we draw most of each sample from the list of registered voters in the state, so for those voters, we can see their actual voting history—not who they voted for but if they voted in each election. I identified everyone we’ve interviewed who remained registered to vote in Wisconsin throughout this entire period, 2020–2026. This includes about 78% of current registered voters in the state and 8,275 respondents to our polls.

I used those respondents to measure the party split among voters at every level of engagement, shown in the graph below.

Republicans enjoy a strong advantage in party ID among those who voted in 7 or fewer of the 11 elections for which they were registered. For instance, about 10% of registered voters voted in only 3 elections, most commonly the three November contests during this period. Among these 3-time voters, our poll finds that 50% identify as Republican, 31% Democratic, and 19% Independent.

Democrats have the advantage with those who voted in 8 or more elections, and the advantage grows steadily with frequency of voting. About 5% of these registered voters had a 100% participation rate; among them, 55% were Democrats, 36% Republicans, and just 9% Independents.

Independents are far less likely to vote frequently. These are “pure” Independents who deny leaning toward either party. Among registered voters who vote the least, more than a fifth are pure Independents. That is more than twice the rate of Independents among high frequency voters.

This means that, as the electorate shrinks, it also becomes more predictable and more ideologically extreme. Among those who voted in two or fewer elections—prototypically, someone who only votes for president, if that—45% describe themselves as moderate, 8% very conservative, and 8% very liberal. Contrast that with the ideology of those who voted all 11 times. Just 20% describe themselves as moderate, 15% very conservative, and 26% very liberal.

In other words, during a high-turnout presidential election, the last voters to be convinced to vote often reject both parties along with the terms “liberal” and “conservative.” A successful politician must appeal to these voters to win in Wisconsin. However, in a low-turnout April election, about 90% of the participants identify with one of the parties and few see themselves as “moderate.” Candidates in these elections play to their respective bases because there is little audience for doing anything else.

Of course, knowing turnout alone can only tell you so much. The qualities of the candidates, the national environment, and other dynamics of the race play a role. But the importance of turnout to shaping the outcome can’t be denied. There were 17 individual contests in the 11 statewide elections from 2020 through April 2026. Here are the results of each of those, compared with the total number of voters in each.

Overall, Republican vote share increases with the size of the electorate. It’s no coincidence that Donald Trump’s 2024 victory coincided with record-breaking turnout in the state.

In general, Republicans remain quite competitive whenever turnout is above 2.5 million. They also won the State Treasurer and U.S. Senator races in 2022. However, no Republican or Republican-endorsed candidate has come within 5 points of victory this decade in a race with turnout below 2.5 million.

Things are particularly dire for Republicans in State Superintendent primaries, when voter turnout can fall below half a million. In 2021 and 2025, multiple Democratic-aligned candidates ran, receiving about two-thirds of the vote combined. Although the single Republican-endorsed candidate in those races still managed to advance to the general election, it’s conceivable that a future February primary could result in two Democratic-aligned State Superintendent candidates advancing to the general.

Given the way that low turnout now works to the benefit of Democrats while Republicans need high turnout to win, it may appear surprising that Democrats remain the party promoting voting access while Republicans pursue efforts that would shrink the electorate. It can seem as if each party is accidentally working to make things better for the other. A few long-standing political beliefs contribute. Many Democrats believe that higher turnout is normatively good, and the Obama-era mindset that “When everyone votes, we win” is still common. Likewise, I suspect many Republicans still believe, despite evidence to the contrary, that the marginal voter is more likely to vote for a Democrat than a Republican.

G. Elliot Morris argues that the polls in Wisconsin underestimated David Crowley’s support in the 2026 Democratic primary because they included too many young voters (who mostly supported Francesca Hong) and too few older voters (who mostly supported Crowley). Using the L2 voter file, he estimates that just 2-3% of a typical partisan primary’s electorate is composed of voters under 30. This analysis is incorrect because the L2 voter file is missing age data for nearly all of the youngest voters, while it includes age data for almost every older voter. Consequently, any estimate of voter participation relying on unaltered L2 age data vastly understates voting participation among young people, specifically.

Morris writes:

I pulled two different pictures of the Wisconsin electorate from the L2 voter file. One universe consisted of of Democrats and nonpartisans who have voted in at least 11% of the even-year primaries they were eligible for. The other was built by taking the L2 list of active voters who cast a ballot in at least one Democratic primary since 2016. The two universes agree with each other almost exactly, which should give us some confidence in the targets being used. Among voters with a known age, both say the primary electorate is about 52-53% seniors and 2-3% under 30.

“Among voters with a known age…” is the key bit. Morris’ analysis would be correct if the missing age data was evenly distributed throughout the population. However, in Wisconsin, it is overwhelmingly concentrated among the young.

The reason for this is simple. Even though Wisconsin collects each voter’s birthday when he or she registers to vote, the state Elections Commission does not sell this information. Wisconsin’s actual public voter file–the one sold by the state–includes scarcely any information about each voter. Here is the list of data elements. Besides election participation records, it includes each voter’s name, address, and contact information. It does not include the voter’s age.

Instead, date of birth is one of the many voter attributes L2 acquires from commercial sources and adds to the Wisconsin voter file before selling it. The older a voter is (and the longer they’ve been registered), the more opportunities L2 has to determine that voter’s birthday. Mechanically, the coverage of the age variable increases with the age of the registrants.

Although the Wisconsin Elections Commission does not sell access to each registrant’s birth date, the WEC does publish a monthly file summarizing the registered voter population by five age ranges. Using that file, we can compare the number of actual registered voters in each age range with the number in L2’s most recent Wisconsin file.

The L2 file only contains birth dates, and thus ages, for 3% of registrants under the age of 25. This grows to 22% among those ages 25-34, and rises steadily thereafter, reaching 94% among voters 65 and up.¹

Excluding voters with missing ages means ignoring the youngest areas of the state. To illustrate: tract #001102 is roughly coeterminous with UW Madison’s campus. Here, the median age is 19 and 99.4% of registration records lack a birth date.

When Morris uses the L2 file to calculate that the typical primary electorate is 2-3% voters under 30, this just reflects the large amount of missing data among young registrants. Among voters with a valid age in the L2 file, just 5% are under the age of 35. Actually, 22.5% of registered voters are this young, according to the official statistics from the WEC.

A better way to measure voter participation

So far, I’ve only been examining voter registration, not election participation, because the WEC does not publish official statistics breaking down each electorate by age. Fortunately, there is another reliable source we can use to measure young people as a share of the electorate.

After every November election, the Census Bureau fields the November Voting and Registration Supplement to its regular Current Population Survey (CPS). This survey is routinely used by pollsters to develop target weights, and it quite closely matches the official statistics published by the WEC.

To demonstrate, the table below shows statistics from the 2024 presidential election in Wisconsin. I compare the actual age breakdown of registered voters from WEC with the results of the CPS November Supplement and registered voter age counts from the L2 file.

Following the 2024 presidential election, 10.2% of Wisconsin’s registered voters were between the ages of 18 and 24. But because L2 had been unable to match birthdays for these relatively new registrants, the file showed that only 0.6% of all registered voters (and 0.8% of those with a valid age) were under the age of 25. In raw numbers, there were 18 times more registrants under 25 in reality than in the L2 file.

The L2 file also lacked birth dates for many registrants ages 25-34. In L2’s data, these comprised 5.8% of registered voters with valid age records, but in reality they made up 14.8%. Meanwhile, the L2 file includes a birth date for almost every older registrant, so when calculated as a proportion of voters with a valid age (as Morris did) they appear grossly overrepresented.

By contrast, the Current Population Survey appears quite accurate. It estimated that adults under 25 made up 9.3% of registered voters in November 2024 compared with the WEC count of 10.2%.

Having verified that the CPS November Supplement accurately captures the age breakdown of Wisconsin’s registered voters, I will now use it to calculate voter participation by age. These statistics are self-reported and subject to normal sampling error, but I tend to trust them, given how closely their age breakdown matches the real WEC stats.

In this table, I adopt the 18-29 year-old age category used by Morris instead of the age bins used by the WEC.

Eighteen-to-twenty-nine-year-olds made up 20% of the adult population in 2024. They accounted for 14% of voters in the November election, according to the CPS. But in the L2 data, voters under 30 were only 3% of voters with a known age. The reason for this is obvious. The L2 file following the 2024 election lacked age data for 938,000 voters, and this included the vast majority of the youngest voters in the state, for whom L2 had so far been unable to add a birth date.

Crowley’s performance

David Crowley remained out of the governor’s race until July 18th. On July 17th, his support was presumably virtually 0%.² By election day on August 11th, his support had reached 40% to Hong’s 39%. The last Marquette Law School Poll was fielded July 22-27. At that time, we found his support was 7% to Hong’s 38%. Plausibly, the Marquette poll underestimated Crowley’s support a week after he reentered the race, but I judge it at least equally plausible that most of Crowley’s gains came in the final two weeks of the campaign.

Whatever the case, a far less likely explanation of Crowley’s success is that the August primary electorate included only 2-3% voters under age 30. That conclusion relies on misunderstanding Wisconsin’s voter file. The version of the file sold by the state does not include age information for any registrant, and the most common commercially available form of the file only reliably adds birth dates for older voters.

Footnotes

1. As of this writing, the most recent L2 file includes state data from June 6, 2026. Comparing that file to contemporaneous data from the WEC shows that about 7% of the state’s registered voters are not included in the L2 list of active registrants at all. These could be individuals who are redacted from the purchaseable voter file due to safety concerns.↩︎
2. It’s true that candidates who’ve dropped out of a race but remain on the ballot receive some of the vote. But most of this can be attributed to early voters casting ballots before a candidate withdraws. In the City of Milwaukee, where I know the composition of election day vs. early voters, Mandela Barnes (who dropped out on July 30th) received 10.4% among early voters but just 0.9% of election day ballots.↩︎

And How Many Early Voters Wasted Their Vote

In Wisconsin, anybody can vote early by mail or in-person at an early voting site for any reason, and many people do. This is referred to, interchangeably, as “early” or “absentee” voting.

In the August 2026 primary, 25.8% of ballots were cast by mail and another 11.9% in-person at an early voting center. Thirty-eight percent of Wisconsin Democrats didn’t wait until election day to cast their ballot in the governor’s primary.

Voting early is risky in a primary election, because the nature of the contest can change a lot in the weeks before a race. The first absentee ballots were sent out in late May and early voting centers opened on July 28th. David Crowley withdrew his candidacy on July 8th. On July 17th, Sara Rodriguez dropped out and Crowley reentered. On July 30th, Mandela Barnes–then polling in second place–ended his campaign. Any voter casting a ballot before July 30th ran the risk of wasting their vote on a candidate no longer running by election day on August 11th.

Statewide, 8.5% of absentee ballots were cast before Crowley dropped out the first time. Thirteen percent were cast while Crowley was officially out of the race but Rodriguez was still in. Then, another 17.7% were cast after Crowley reentered but before Barnes dropped out. Across Wisconsin, 39% of early voters cast their ballot before the final field was set.

How many of them voted for a candidate who subsequently dropped out? Doubtlessly, some of them. According to the Associated Press on Wednesday afternoon, the three suspended campaigns (Rodriguez, Barnes, and Hughes) collectively received 68,343 votes, or 8.6% of the total. Recall that Crowley defeated Hong by about 3,800 votes.

In most places, it is impossible to tell who those early voters voted for, because their ballots are counted along with those of regular, election day voters at each individual polling place. The complete results for each ward are reported one time, including ballots from every mode of voting.

However, many larger municipalities count their early votes separately at a central count location. The City of Milwaukee is one of these. In Milwaukee, the process of counting absentee ballots often drags on late into the night, well after the election day results from each ward have been tallied and published. Because Milwaukee always has tens of thousands of absentee ballots, this means that close statewide elections can never be called until those votes are reported–a process that occurs all at once and involves some drama as elections officials (accompanied by a police escort) transfer thumb drives containing the absentee results from the central count location to the courthouse. Once the thumb drives arrive, the early votes are added to the ward totals where each voter would’ve gone had they voted on election day. This instantaneous addition of thousands of votes to Milwaukee’s total is commonly called the “ballot dump.”

The ballot dump causes much angst in Wisconsin by providing fodder for conspiracy theorists who watch Milwaukee’s late addition of votes lift Democratic candidates to victory, as happened in 2018, 2020, and 2024. In fact, state law prohibits Milwaukee’s election commission from taking steps to speed up their central count, such as pre-processing absentee ballot signatures and envelopes before election day, and Republican legislative leadership killed a bipartisan bill aimed at reforming this in 2023.

As bad as these late-night ballot updates are for confidence in our elections, they are useful for researchers like me. We can use them to measure differences between the early vote and the election day vote. The contents of the early vote ballot dump are not explicitly reported, but by subtracting the election day totals for each ward from the final, complete totals, we can see exactly how early voters cast their ballots.

Crowley led Hong by just over 1,000 votes in Milwaukee’s election day returns, and he doubled that raw vote lead once the city’s absentee ballots were added. Unlike in several previous general elections, Milwaukee’s late night ballot dump did not change the leader of the 2026 Democratic primary. The added ballots merely added to the lead he already held in AP’s running tally. When it was all said and done, the City of Milwaukee was not individually decisive in Crowley’s statewide victory. He won the state by around 3,800 votes. Of that victory margin, the City of Milwaukee contributed about 2,200 votes–half from early voters and half from election day ballots.

Milwaukeeans who cast their ballots early did waste their votes at a much higher rate. This table shows the share received by each candidate listed on the ballot among early vs. election day voters.

Sara Rodriguez, who ended her campaign on July 17th, received 7% of early votes and only 0.6% of election day ballots. Mandela Barnes, who dropped out on July 30th, took 10.4% among early voters but just 0.9% on election day.

All told, 17.7% of early voters voted for somebody who dropped out before the election, compared to just 1.6% of election day voters. In this way, election day voters appear to have been very well informed about which candidates remained actively in the running.

People who waited to vote until election day also appear to have consolidated more behind one of the two front-runners. Joel Brennan and Kelda Roys remained in the race until the very end, but they never drew much support. Combined, 9.2% of Milwaukee’s early voters picked one of these minor candidates. This fell to 5.3% by election day.

As discussed above, Crowley received a similar number of net votes (relative to Hong) in both the election day totals and the smaller absentee totals. But in percentage terms, Crowley actually did better with early voters, among whom he beat Hong by 4.4 points, than among election day voters, among whom his margin of victory shrank to 1.8 points. By the end of the race, Milwaukee’s Democratic primary voters had thoroughly consolidated behind the two frontrunners, with Hong winning 45.6% of election day voters to Crowley’s 47.4%.