(Bloomberg) -- State Senator Leah Vukmir won Wisconsin’s Republican U.S. Senate primary Tuesday night after a campaign that pitted two of the nation’s top GOP donors against each other in a divisive and costly battle that Democrats hope will boost their prospects of holding the seat in November.

Vukmir beat businessman and Marine Corps veteran Kevin Nicholson and will face Democratic Senator Tammy Baldwin, who is seeking a second term in a state President Donald Trump won by eight-tenths of a percentage point in 2016.

Roofing supply billionaire Diane Hendricks backed Vukmir and Dick Uihlein, an Illinois resident who owns a Wisconsin shipping and packaging materials company, had supported Nicholson. Outside groups, including those heavily backed by the two mega donors, spent at least $17.8 million ahead of the primary.

In neighboring Minnesota, Hennepin County commissioner Jeff Johnson beat former Governor Tim Pawlenty in the Republican primary to replace outgoing Democratic Governor Mark Dayton.

Pawlenty, who briefly ran for president in 2012 and was sharply critical of Trump in 2016, had resigned a $2.6-million-year position earlier this year as head of the Washington-based Financial Services Roundtable, a group that lobbies for U.S. banks and insurance, asset management and credit card companies, to run for his old job.

Primaries Winding Down

Primaries were also held Tuesday in Connecticut and Vermont as the nomination season enters its final month and just 10 states remain to pick their candidates for the general election. Voters narrowed the field in numerous competitive districts that will help determine whether Democrats can flip at least 23 Republican-held seats to win a majority in the House. They’ll have a tougher time gaining control of the Senate, where Democrats have 26 seats to defend, compared with just eight for the GOP.

In Wisconsin’s Democratic primary for governor, state education superintendent Tony Evers won a contest that had 10 candidates on the ballot seeking to prevent Republican Scott Walker from winning a third term. Walker easily won renomination, but his approval rating was 47 percent in a recent state poll and he’s repeatedly warned his supporters of a possible "blue wave" this year.

In the contest to fill the southeastern Wisconsin seat being left open by House Speaker Paul Ryan’s retirement, Republican Bryan Steil, a lawyer and former Ryan aide, will face a Democratic Randy Bryce, an iron worker and Army veteran who has gained a national following. Bryce has raised $6.3 million, but he’s got an uphill climb in a district Ryan routinely won easily and Trump carried by 10 percentage points in 2016.

Trump Comparisons

As has been the case in other contests this year, Trump’s shadow loomed over Wisconsin’s balloting.

Nicholson, a business consultant, sought to use Vukmir’s political experience against her while selling himself as a Trump-like outsider. The one-time Democrat pointed to Vukmir’s statements that Trump is offensive, which were caught on video during the 2016 presidential primary.

Vukmir and Nicholson fought over who was more closely aligned with the president -- a position that may be less helpful in the general election. Vukmir, a longtime ally of Walker, had the backing of top Republicans in the state, including Ryan.

Harley Boycott

Walker, who lost out to Trump in a bid for the 2016 Republican presidential nomination, had been put in the awkward spot just ahead of the primary of answering questions about Trump’s promotion of a boycott of a Wisconsin-based Harley-Davidson Inc.

The iconic American motorcycle manufacturer has said tariffs enacted by the European Union in response to Trump’s penalties on imported steel and aluminum would add as much as $100 million a year to its costs. The company said that means it must shift production outside the U.S. for EU customers, prompting Trump to lash out.

On Defensive

Walker has avoided directly criticizing the president for blasting one of his state’s top companies and instead expressed his support for free trade.

The governor has also been put on the defensive over voter concerns about government subsidies he’s supported for Foxconn Technology Group, which plans to build an electronic screen manufacturing campus that may eventually employ 13,000 in southeast Wisconsin.

Representative Tim Walz won the Democratic nomination for governor in Minnesota, a state Democratic presidential nominee Hillary Clinton carried by 1.5 percentage points.

Minnesota voters picked nominees for two U.S. Senate, an unusual circumstance triggered by the resignation of former Senator Al Franken amid sexual misconduct allegations. Incumbent Democratic senators Amy Klobuchar and Tina Smith will face state Representative Jim Newberger and state Senator Karin Housley, both Republicans.

Minnesota will also play a key role in the fight for control of the U.S. House. Four of the state’s eight districts are rated as tossups by the nonpartisan Cook Political Report. Only California, which is seven times as populous, has that many.

Tossup Contests

Among the four tossup seats, two Republican congressmen, Jason Lewis and Erik Paulsen, face serious Democratic challengers, while two Democrats are leaving seats in districts where Republicans are competitive.

Angie Craig, a former health-care executive, won the Democratic-Farmer-Labor Party’s nomination to challenge Lewis in the 2nd District and wealthy businessman Dean Phillips won the party’s nod to take on Paulsen in the 3rd District.

In northern Minnesota’s 8th District, where Trump has greater popularity, Republican Pete Stauber will face former Democratic state Representative Joe Radinovich.

In southeastern Minnesota’s 1st District, Dan Feehan, an Army veteran and Defense Department official in the Obama administration, won the Democratic nomination for a seat now held by Walz. Republican voters selected Jim Hagedorn, a former Treasury Department official who came within one percentage point of unseating Walz in 2016.

Representative Keith Ellison, the Democratic National Committee’s deputy chairman, won his party’s backing for state attorney general after he was accused this past weekend of domestic violence against a former girlfriend. Ellison, who was endorsed by Senator Bernie Sanders, has denied the allegations.

In Connecticut, Democratic Senator Chris Murphy faced no primary challenge. The outspoken supporter of gun control is seeking a second term and will face Republican small-business owner Matthew Corey in a race Cook rates as “Solid Democratic.”

Wealthy Greenwich businessman Ned Lamont won the Democratic nomination in the race to replace Democratic Governor Dannel Malloy. Former investment banker Bob Stefanowski won the Republican primary for governor.

Sanders, a two-term independent who caucuses with Democrats, easily won the Democratic nomination in Vermont. The 2016 presidential candidate will face a Republican in a race that hadn’t yet been called in a state Trump lost by 26 percentage points.

Christine Hallquist, a former utility chief executive who is the first transgender major-party candidate nominated for governor, won Vermont’s Democratic primary for governor and will face incumbent Republican Governor Phil Scott in race rated "Solid Republican" by Cook.

(Updates with Pawlenty loss in fourth paragraph.)

To contact the reporter on this story: John McCormick in Chicago at jmccormick16@bloomberg.net

To contact the editors responsible for this story: Joe Sobczyk at jsobczyk@bloomberg.net, Justin Blum

©2018 Bloomberg L.P.