The battle for control of Congress continues Tuesday as voters in four states — Wisconsin, Minnesota, Vermont and Connecticut — head to the polls for their primaries. 

Some of the most closely watched races include Wisconsin’s U.S. Senate election, in which Republican Sen. Ron Johnson figures to face a tough challenge; a Minnesota U.S. House race to decide the late Jim Hagedorn’s successor; and Vermont’s U.S. Senate election for a seat that is open for the first time in nearly a half-century, as Patrick Leahy retires.

Wisconsin

As Democrats try to cling to control of the Senate, Johnson’s seat is one they’re hoping to flip.

In a state President Joe Biden won in 2020, Johnson had just a 37% approval rating in a June poll by Marquette University Law School.

First elected in 2010, Johnson has generated national headlines for spreading misinformation about COVID-19 vaccines, the 2020 presidential election and the Jan. 6 insurrection. He’s also come under fire after the House Jan. 6 committee revealed his chief of staff tried to deliver lists of fake, pro-Trump electors to then-Vice President Mike Pence as former President Donald Trump and his allies sought to subvert the election results. (Johnson has claimed he “had no hand in it.”)

Johnson’s lone challenger in the Republican primary is retired educator David Schroeder.

But five candidates are vying for the Democratic nomination in the race. Lt. Gov Mandela Barnes has led the field in fundraising and secured high-profile endorsements from Sens. Bernie Sanders and Elizabeth Warren and Reps. Alexandria Ocasio-Cortez and Jim Clyburn. Johnson and Republicans already are attacking Barnes, who supports the Green New Deal and Medicaid for all, as too liberal for the state.  

Other Democrats running include restaurant owner Kou Lee, musician Steven Olikara, investigative reporter and lawyer Peter Peckarsky, and state emergency management administrator Darrell Williams.

Despite Johnson’s low approval rating, the Marquette poll found him narrowly trailing Barnes 46% to 44% in a possible head-to-head matchup in November.

Of Wisconsin’s eight House races, the Cook Political Report rates only the 3rd District as competitive. Democrat Ron Kind, who’s held the seat since 1997, is retiring. 

Derrick Van Orden, who lost to Kind in 2020 and — despite his denials — was reportedly on the Capitol grounds during the Jan. 6 insurrection, is running unopposed for the Republican nomination.

Four Democrats are competing to face Van Orden. They include former CIA officer Deb Baldus McGrath, physician and La Crosse City Councilman Mark Neumann, small-business owner and Economic Development Council member Rebecca Cooke and state Sen. Brad Pfaff, a former aide to Kind. 

Meanwhile in state races, four Republicans are competing for the chance to take on incumbent Democratic Gov. Tony Evers this fall. Marquette’s June poll had the race neck-and-neck between former Lt. Gov. Rebecca Kleefisch and construction executive Tim Michels, who has Trump's endorsement.

The state’s lieutenant governor and secretary of state races could also have significant impacts on abortion rights and elections. Incumbent Attorney General Josh Kaul refuses to enforce the state’s 1849 abortion ban, but two of the top GOP challengers say they would. 

Meanwhile, Republicans say they want to dismantle the elections commission and give the secretary of state the power to oversee elections. All three GOP candidates in the secretary of state race support such a change and have repeated Trump’s false claims that fraud cost him the 2020 election.

Minnesota

Voters in Minnesota’s 1st Congressional District will vote in a special election Tuesday to determine who will replace Hagedorn, a Republican who died of kidney cancer in February, for the remaining months of his term. And most of them also will vote on who will fill the seat when a new Congress convenes in January.

The dual races have created some complicated campaigning dynamics. For instance, Republican Brad Finstad, a former U.S. Agriculture Department official, is simultaneously facing a Democratic opponent in the special election — former Hormel Foods CEO Jeffrey Ettinger — and rematching a Republican foe whom he defeated by just 427 votes in the special election primary in May — state Rep. Jeremy Munson.

Ettinger, who won 64% of the vote in the Democratic special election primary, is up against just two opponents in the general race, compared to seven in May. But James Rainwater and George Kalberer face long odds after they received 2.4% and 0.7% of the vote, respectively, last time around.

Due to redistricting, some voters in the district, which stretches across the state’s southern border, will only be allowed to vote in the special election. 

The Cook Political Report rates the seat as competitive, but leaning Republican. 

Rep. Ilhan Omar, D-Minn. (AP Photo, File)

In the 5th District, progressive incumbent Ilhan Omar faces four challengers, including former Minneapolis City Councilman Don Samuels, who is being backed by several former Minnesota mayors. Samuels has played up his support for law enforcement while attacking Omar for pushing for the dismantling of the Minneapolis Police Department.

Minnesota’s 2nd Congressional District is rated as a toss-up, but that primary was canceled because Democratic incumbent Angie Craig and Republican challenger Tyler Kistner were unopposed for the party nominations. They also squared off in 2020.

In the state’s gubernatorial race, incumbent Tim Walz faces perennial candidate Ole Savior for the Democratic nomination. Three hopefuls are competing in the GOP primary: Doctor and former state Sen. Scott Jensen — who has been endorsed by the Republican Party — former TV reporter and producer Joyce Lacey, and Bob Carney Jr., who, like Savior, also has an extensive history of running for offices.

Minnesota’s secretary of state race, meanwhile, includes a Republican candidate, Kim Crockett, who has called the 2020 election “rigged” and  showed a video at the state party convention depicting billionaire investor and philanthropist George Soros as a puppet master, pulling the strings of Steve Simon, the current secretary of state, and prominent election lawyer Marc Elias, with a caption that said, “Let’s wreck elections forever and ever and ever.”

All three men are Jewish. The GOP state chairman soon apologized, claiming Crockett did not intend for it to be antisemitic. Crockett did not apologize, and a day after the chairman’s apology, sent a fundraising letter with the title “Media smears and communist tears” and claiming she was the victim of “contrived and bogus political attacks.”

Vermont

The U.S. Senate seat that has been occupied by Leahy, a Democrat, since 1975 is up for grabs, with three Democrats, three Republicans and several independents and third-party candidates vying for it.

The Cook Political Report rates the race as solidly Democrat, and U.S. Rep. Peter Welch has a commanding lead in the polls and in fundraising over activist Isaac Evans-Frantz and emergency physician Niki Thran in the Democratic primary. 

Christina Nolan, a U.S. attorney during the Trump administration, Army veteran Gerald Malloy and investment banker Myers Mermel are running for the GOP nomination.

Meanwhile, Welch’s Senate candidacy has left Vermont’s at-large House seat open and might lead to the state sending a woman to Congress for the first time. It is the only state that has not had a female Congress member.

Vermont state Senate President Becca Balint (AP Photo, File)

In the Democratic primary, polls show state Senate President Becca Balint with a wide lead over Lt. Gov. Molly Gray and physician Louis Meyers.

The GOP field includes Marine Corps veteran Liam Madden, accountant Ericka Redic and Anya Tynio, a Republican Party official in Orleans County.

Incumbent Gov. Phil Scott, a Republican, faces two challengers in Tuesday’s primary: landscaping contractor Stephen Bellows and Peter Duval, who was recalled from the selectboard in Underhill in 2021.

The Republican winner will face activist Brenda Siegel, who was unopposed for the Democratic nomination, in November.

Vermont holds gubernatorial elections every two years.

Connecticut

Three Republicans are vying for the opportunity to face Democratic incumbent Sen. Richard Blumenthal in November.

Former Connecticut state House Minority Leader Themis Klarides (AP Photo, File)

The field includes former state House Minority Leader Themis Klarides, businesswoman Leora Levy and businessman Peter Lumai. A May poll from The Hill and Emerson College found that Klarides has the best shot to beat Blumenthal, but she still trailed by 10 points (50% to 40% with 10% undecided).

Connecticut has not been represented by a Republican senator since Lowell Weicker left office in January 1989.

Two of Connecticut’s five U.S. House seats are rated as competitive this year, but the primaries — both for seats currently held by Democrats — were canceled because there was no competition for either parties’ nominations.

In the 2nd District, incumbent Joe Courtney will face Republican state legislator Mike France in the general election, while Jahana Hayes seeks reelection in the 5th District against Republican George Logan, a former state senator.

The Associated Press contributed to this report.