Top Wisconsin Senate races, 2026

With 4 top races, Democrats need 3 wins to gain the majority

The Wisconsin state Senate is up for grabs in 2026, for the first time since 2012. There are four seats widely seen as the top competitive races, three held by Republican incumbents and one by a Democrat.

On January 22, one of those Republicans, Rob Hutton, R-Brookfield in the 5th district, announced he will not seek reelection. State Assembly Rep. Robyn Vining, D-Wauwatosa and community advocate Sarah Harrison have announced candidacies. The State Senate Democratic Committee has endorsed Vining.

Hutton’s district in a suburban area west of Milwaukee, in eastern Waukesha county. Yes, crucial Waukesha county.

In the Senate, three Republicans hold seats that Democrat Kamala Harris won in 2024, one of those held by Hutton. No Democratic incumbent holds a seat that Republican Donald Trump won in 2024. One Democratic incumbent holds a seat that was narrowly won by Harris. These four seats are widely seen as the top races in 2026. Hutton’s retirement can only make the race for the 5th more of a Democratic pickup opportunity.

The table lists these incumbents, their districts and the 2024 presidential vote margin, as well as cash on hand as of Dec. 31st. The 2026 Wisconsin Senate races are those in odd numbered districts. These senators did not face election in 2024 in their new districts. For that reason we measure competitiveness by the presidential vote margin in 2024 and any split between the incumbent’s party and the party of the presidential winner in that new district.

In 2024, Harris won SD5 by 6 percentage points, making it easily the most lopsided of the four battleground seats. The other two split outcome Republican seats were won by Harris by just 1 point each. The Democratic held seat, the 31st, was won by Harris by 2 points. That district will pit two incumbents against one another in 2026, with Sen. Jesse James choosing to give up his quite safe 23rd district to run against Jeff Smith in the close 31st.

All past votes in this analysis are votes for statewide candidates within the current district lines. This allows comparison of voting trends since 2012 for the current district boundaries. This makes it clear that the districts designed by Democratic Gov. Tony Evers in the 2024 redistricting have put all three Republicans in newly challenging districts. The figure shows the votes for statewide races since 2012 in the new district boundaries.

In Hutton’s 5th there has been a very strong movement away from GOP majorities to moderate Democratic wins since 2020. Marklein’s new 17th district has been strongly Democratic since 2012, though with a close Harris win in 2024. Marklein brings a large war chest to the race, in which he is facing Democratic Assembly Rep. Jenna Jacobson, D-Oregon. Wanggaard’s 21st has also drifted Democratic, though not so much as the 5th. (As of Jan. 22, Wanggaard has not announced his decision on seeking reelection.) Smith’s 31st is fairly Democratic in all elections since 2016, with a somewhat close Harris win in 2024. Large liberal margins in the 2025 Supreme Court race stand out in each of the 4 districts, though that race was more lopsided statewide than any other except the 2018 U.S. Senate election.

Given the close presidential margins in the 17th and 21st, it is plausible that incumbent Republicans could hold these seats, though the past voting record in the 17th is especially challenging.

Republicans currently have an 18-15 majority in the Senate, so Democrats have to win at least three of these four races to pick up a narrow majority.

Thirty years of Wisconsin Supreme Court Elections

Wisconsin’s Supreme Court elections were once low-key, low-turnout April affairs. Not so much any more. In 2023 total spending on the court race reached $50 million. Two years later, in 2025, total spending doubled that, passing $100 million. The big spending reflects the stakes in a shifting majority on the court. In the 2019-20 term, conservatives held a 5-2 majority. In 2020 liberals narrowed the conservative majority to 4-3. After the 2023 election it became a 4-3 liberal majority, which was maintained in 2025. With a retiring conservative justice, the 2026 election can either hold the 4-3 liberal majority or increase it to 5-2 for the 2026-27 term. (The seven justices are elected to 10 year terms.)

This recent shift contrasts with consistent conservative majorities from 1995 until the recent shifts. The figure shows the results of court elections since 1995. From 1995 through 2003 conservatives won 5 elections to 2 for liberals. From 2005 to 2013 conservatives again won 5 elections to 2 for liberals. But since 2015 liberals have won 5 seats to 3 for conservatives.

Since the 1990s Wisconsin Supreme Court elections have become far more partisan with voting patterns coming to be strongly linked to partisan elections and with the parties endorsing and financially supporting candidates in the formally non-partisan court races.

The next figure shows this changing partisan structure to court voting. As an example, I use Justice Ann Walsh Bradley, who won in 1995 and 2015 before retiring in 2025. (In 2005 she ran unopposed.) In 1995, there was a moderate correlation, .45, between how counties voted for the court race and how they voted in the previous presidential race. But by 2015, the correlation between Bradley’s vote and the 2012 presidential vote had risen to .78. In 2025 when Bradley retired, the correlation for liberal Susan Crawford with the 2024 presidential vote was an astonishing .99. This reflects the surge in party polarization in Wisconsin and the emergence of court races more tightly tied to partisan divisions.

This increase in partisan voting structure is not a sudden phenomena, but one which has grown steadily since the 1990s. In the 1970s and 1980s there was little partisan structure to court elections. Indeed, in 1978 the correlation was nil, .002. This rose sporadically in the 1990s, then grew steadily since 2007 to the current astonishingly high .99 of 2025.

This extremely high correlation doesn’t mean outcomes are locked in. Justice Brian Hagedorn, a conservative, won in 2019 by less than a 1 percentage point margin, with a correlation of .92 with the 2016 outcome, while Justice Rebecca Dallet, a liberal, won the year before with a 10 point margin and a correlation of .89 with the same 2016 presidential race. If all counties shift their votes up or down by the same amount, the correlation remains high though the outcome can shift, as in these two cases. Correlation tells us about the structure of the votes but not where the majority necessarily falls. What we have now is that the most Republican counties are now virtually certain to also be the most conservative in their court votes and the most Democratic counties the most liberal. That wasn’t the case before the 1990s when knowing a county’s presidential vote told us very little about their court vote.

The April 2026 election is likely to reflect this strong partisan structure of voting, though we can’t yet say if the net election forces will shift in the liberal or conservative direction.

The geography of the court vote has shifted dramatically over 30 years. In 1995, liberal Justice Bradley won with 55% of the vote. In 2025, liberal Justice Crawford replaced the retiring Bradley with a nearly identical 55% of the vote. But the sources of these two victories was dramatically different. In 1995, Bradley was strongly supported in the north, north-central, and southwestern parts of the state. Notably her vote was significantly less in Brown, Dane and Milwaukee counties. In 2025, Crawford lost badly in the north, north-central and most of the southeast, while she ran up large margins in Dane and Milwaukee, much more than Bradley’s 1995 totals in those counties. She also ran a little ahead in Brown, a county Bradley had lost badly in 1995. The maps shows how dramatically the geography of the vote has shifted even with identical vote margins in the two races.

With so much of the state shifting from blue to red, how is it that the vote margin is unchanged? Democratic gains have been large and come in counties with large populations. Republican gains are widespread but mostly in less populous counties. In large Republican leaning counties, Waukesha, for example, the conservative majority has increased but only slightly, with a larger increase in Washington, but a slight decrease in Ozaukee. Republicans have gained in Marathon, but the conservative margin is only moderate.In contrast, Dane has gone from pretty liberal to overwhelmingly liberal, and Milwaukee which was quite competitive has also become very liberal in its court vote. These shifts also highlight the greater geographic polarization in the 2020s compared to the 1990s, while not shifting the statewide balance at all.

Public opinion

Since 2023 the Wisconsin Supreme Court has held a consistent net approval rating, though about 15% say they don’t have an opinion. Court approval slightly improved during and after the 2025 court election, declining slightly in October.

As of October, the candidates for the court in 2026 were little known to the public. This is not unusual in court elections and especially so with no incumbent. The Marquette Law School poll in October asked registered voters if they had a clear idea what the candidates stand for. For both candidates, 69% said they hadn’t heard enough, and only 10% or 11% said they did have a clear idea. With less than 3 months left before the April election, the campaigns have a lot of messaging to do.

Voters have a strong preference that candidates for the court discuss issues so voters know what they stand for, 83%, while only 17% say candidates should avoid discussing issues so as to not appear to have prejudged issues. On this, partisans and independents are in agreement.

The balance of the court

With the current balance of the court, and the justices coming up for election in the next 10 years, the liberal majority is assured until at least 2028. Should the liberal candidate win in 2026 the majority will remain in liberal hands until at least 2030 (absent an unscheduled vacancy occuring.)

After more than two decades of conservative majorities, the liberal victories in five of the last eight court elections has altered the balance, and created the prospect for continued majorities well into the 2020s or beyond.

The shifting balance of the court since 2019 is shown in the table below.

And for those who want way more detail (you know who you are), here are all Wisconsin Supreme Court elections since 1976. My ideological classification of justices may be debatable in some cases prior to 2000. In those less partisan times ideology played less of a role and moderate justices may be mislabled. The distinctions since 1995 are much more clear, though note that Hagedorn was elected as a conservative candidate but does not align strongly with either the liberal or conservative wings of the court in his decisions, siding with conservatives a little more than half the time in some terms and a little more than half with liberals in other terms. See the excellent SCOWstats.com for detailed analysis of court alignments since 1918.