Voters in four states head to the polls Tuesday to weigh in on key congressional and gubernatorial primaries, with fewer than 100 days to go before Election Day.  

In Missouri, a high-profile House primary is highlighting divides among Democrats over the conflict in Gaza and threatens to oust a member of the progressive “squad.” In Michigan, November match-ups will be set in the race to replace retiring Sen. Debbie Stabenow (D) as Democrats battle to hold onto the upper chamber.  

Ballots will also be cast in Kansas and Washington state, just weeks after the major shakeup at the top of the Democrats’ presidential ticket and just ahead of the party’s convention later this month.  

Here are the five races to watch Tuesday: 

Cori Bush faces formidable challenge 

Progressive Rep. Cori Bush (D-Mo.) is defending her seat in the House against a formidable Democratic challenger, St. Louis County prosecutor Wesley Bell, in a race that could deal yet another blow to the “squad” on Capitol Hill.  

The race has highlighted divides in the Democratic party over the Israel-Hamas war in Gaza. Bush has taken a strong stance against Israel’s response to the Hamas attack that kicked off the conflict and was among a small handful of House members who opposed a resolution that expressed support for Israel.  

Her position has upset many establishment Democrats. The American Israel Public Affairs Committee’s (AIPAC) pro-Israel super PAC, which helped oust fellow progressive Rep. Jamaal Bowman (D) in New York earlier this year, is part of a national push to unseat Bush.  

Her challenger, with AIPAC’s backing, has suggested Bush is too disruptive, echoing frustration from moderates. The St. Louis Post-Dispatch’s editorial board similarly admonished the incumbent as they backed her challenger. 

Both candidates entered the political spotlight in the aftermath of the 2014 police shooting of Michael Brown in Ferguson. Bell ousted a longtime incumbent to win his prosecutor seat in 2018, promising to bring justice to the Brown family, while Bush was elected to the lower chamber in 2020, pointing to her time as a Ferguson activist as her prompt to seek higher office. Last year, Bell decided against a Senate bid to vie for Bush’s seat.  

The district is heavily Democratic, and the primary winner will be the heavy favorite in November, but Tuesday’s contest is set to be a tight race. A June poll put Bush and Bell in a dead heat, stoking concerns about a second Squad defeat this cycle.  

Michigan primaries in race for Stabenow seat  

The Democratic primary for Stabenow’s seat in the Great Lakes State could play a big role in deciding control of the Senate this fall.  

Three-term Rep. Elissa Slotkin (D-Mich.) is the leading candidate for the open seat after Stabenow decided against seeking a fifth term in the upper chamber, promising to “pass the torch” to a new generation of lawmakers. Actor Hill Harper, who left ABC’s “The Good Doctor” to launch his campaign, is also in the ring.  

But Stabenow’s retirement also created a sought-after pickup opportunity for Republicans, who have said this cycle presents their best chance in years to win the Senate, with an expanded battlefield and strong recruits.  

The winner of the Democratic primary on Tuesday is expected to go up against former Rep. Mike Rogers (Mich.), the GOP primary front-runner backed by former President Trump.  

Slotkin has a strong record in her previous House races for her Lansing-area district. Polling averages from The Hill and Decision Desk HQ show her with a 6-point lead over Rogers, and forecasts show her with a 66 percent chance of winning the state if they go head-to-head.  

Michigan will also be critical in the presidential race. Slotkin raised concerns last month that President Biden, before his historic exit from the 2024 race, was trailing Trump in private state polls. Biden saw significant protest votes from within his party during the state’s primary earlier this year as progressives and Arab Americans voiced frustration over his handling of the war in Gaza. 

But an early poll from Bloomberg News/Morning Consult showed Harris with a promising lead over Trump in the critical swing state, though it’s still unclear how the newly shaken-up presidential ticket could impact key races down ballot. 

Three Republicans duke it out for Missouri governor 

Nine candidates are vying for the Republican nod to replace term-limited Gov. Mike Parson (R), with three candidates emerging as the leading front-runners: Missouri Secretary of State Jay Ashcroft, Lt. Gov. Mike Kehoe and state Sen. Bill Eigel. 

All three of them have notably attracted the endorsement of, who wrote on Truth Social last month, “They are MAGA and America First all the way! I can’t hurt two of them by Endorsing one so, therefore, I’m going to Endorse, for Governor of the Great State of Missouri, Jay Ashcroft, Mike Kehoe, and Bill Eigel. Choose any one of them – You can’t go wrong!” 

Ashcroft, whose father is former Missouri Gov. John Ashcroft, has also racked up endorsements from former acting Director of United States National Intelligence Richard Grenell, former Director of National Intelligence John Ratcliffe and former Arkansas Gov. Mike Huckabee (R). 

Kehoe has attracted other endorsements from Parson and other groups, like the Missouri Farm Bureau’s PAC and the Missouri Fraternal Order of Police. Sen. Mike Lee (R-Utah) endorsed Eigel.  

Whoever wins the GOP primary is likely to take on either Democrat businessman Mike Hamra or House Minority Leader Crystal Quade (D). The nonpartisan election handicapper Cook Political Report rates the seat “solid Republican.” 

A sitting attorney general takes on one of Trump’s lawyers 

Missouri Attorney General Andrew Bailey was appointed to his position in 2022 by Parson after Sen. Eric Schmitt (R-Mo.) won a seat in the Senate last cycle. Bailey is running for his first four-year term against Trump lawyer Will Scharf in the GOP primary for Missouri attorney general.  

Scharf is an appellate attorney for Trump who has represented the former president in two appeals arising from his federal election subversion case: his gag order and presidential immunity defense. Scharf has also represented Trump in some appeals arising from the sexual abuse and defamation lawsuits brought by advice columnist E. Jean Carroll. 

Similar to Trump’s move to endorse three front-runners in the Missouri gubernatorial GOP primary, the former president endorsed Bailey and Scharf, who served previously as an assistant U.S. attorney in the state, in the Republican contest for attorney general.  

The race has seen millions of dollars in outside spending, notable because lower-ballot races generally don’t attract that kind of money.  

A Republican who voted to impeach Trump vies for reelection 

Rep. Dan Newhouse (R-Wash.), who was one of 10 House Republicans who voted to impeach Trump and is only one of two pro-impeachment lawmakers left in the lower chamber, is vying for reelection.  

He faces seven contenders in his primary for Washington’s 4th Congressional District, including Republicans Jerrod Sessler, a former NASCAR driver and Navy vet who has Trump’s endorsement, and former Senate candidate Tiffany Smiley.  

Washington has a top-two open primary system, meaning all the candidates running for office, regardless of party affiliation, are placed on the same ballot. The top-two finishers then go head-to-head in November.  

Sessler ran against Newhouse in the GOP primary last cycle, placing fourth with 12 percent of the vote. Smiley ran against Sen. Patty Murphy (D-Wash.) last cycle and lost by close to 15 points.  

Trump won Newhouse’s district in 2020 by roughly 17 points, meaning Republicans are the heavy favorite to hold the seat in November.