The midterm primary rush continues Tuesday as voters in six states cast their ballots in high-stakes contests that could play a huge role in deciding which party wins control of Congress in November.

Two of the most closely watched races are in California. The Golden State will elect a new governor this year, and Tuesday’s primary could effectively decide who ends up leading the country’s most populous state.

There are more than 60 candidates on the ballot, including a crowded field of Democrats vying to replace outgoing incumbent Gavin Newsom, who is widely expected to launch a presidential bid in 2028. The contest got a major shake-up in April, when then-Rep. Eric Swalwell, who had been toward the top of most polls, dropped out amid allegations of sexual misconduct made by several women. Since Swalwell’s exit, former Health and Human Services Secretary Xavier Becerra has emerged as the slight favorite among Democrats, with billionaire Tom Steyer trailing a few points behind.

California uses an open primary system in which the top two vote-getters, regardless of party, move on to the general election. This unique system creates a slim possibility that two Republicans could emerge from the primary if the Democratic vote gets split between too many candidates. If that happens, California would be guaranteed to have its first GOP governor since Arnold Schwarzenegger.

The night’s other high-profile race is in Los Angeles, where Democratic Mayor Karen Bass is running for reelection while facing tough challenges from Republican former reality star Spencer Pratt and progressive Democrat Nithya Raman. A new poll shows the three candidates in an extremely close race. If no one receives 50% of the vote, which appears likely, the top two finishers will move on to a runoff. That same poll suggested that Pratt would be a substantial underdog in a head-to-head matchup against either Democrat if he qualifies for the runoff.

California isn’t the only state with important primaries on Tuesday. In Iowa, Democrats’ hopes of flipping a key Senate seat could hinge on the results of a tight primary between state lawmakers Josh Turek and Zach Wahls. The Hawkeye State hasn’t elected a Democrat to the Senate since 2008, but polls suggest both of the party’s candidates might have a chance of defeating the likely Republican nominee, Rep. Ashley Hinson.

Montana has only two congressional districts, and one of them might see closely contested primaries on both sides. In the First District, where the Republican candidate received only 52% of the vote in 2024, former state lawmaker Al Olszewski will face conservative radio host Aaron Flint in the GOP primary, while four Democrats have entered their party’s primary.

In New Jersey, four Democrats are vying for their party’s nomination in the state’s Seventh District. Incumbent Republican Tom Kean Jr. was already seen as vulnerable before he began an extended absence due to an unspecified health issue that has kept him from appearing on Capitol Hill for more than two months. Crowded doesn’t even begin to describe the field in New Jersey’s 12th District, where over a dozen Democrats have entered the primary.

South Dakota’s Republican Gov. Larry Rhoden, who became governor after Trump named Kristi Noem as homeland security secretary last year, is running for reelection. Polls show that he is at risk of being ousted by challengers from within his own party, specifically Rep. Dusty Johnson and businessman Toby Doeden. If no one receives 35% of the vote on Tuesday, the race will head to a runoff.

New Mexico will also be holding its primary on Tuesday, but there appear to be clear frontrunners in every major race on the ballot. Incumbent Democratic Sen. Ben Ray Luján looks to have a clear path to his party’s nomination as he pursues reelection. The same goes for former Interior Secretary Deb Haaland, who’s running for governor.

There are many more important dates on the primary calendar as the road to the midterms continues to heat up. Here are more races to watch across the country.

Sen. Susan Collins of Maine is widely viewed as one of the most vulnerable Republican senators. The Democratic contest to choose her challenger was one of the most closely watched primary races in the country. But the drama ended in late April when the state’s governor, Janet Mills, dropped out. That left political newcomer Graham Platner with a clear path to his party’s nomination.

All four of Nevada’s House districts in 2024 were won by candidates who received 55% of the vote or less. Multiple Republicans have jumped into the GOP primaries in the state’s three Democrat-held seats. The primaries are especially crowded in Nevada’s Second District, where candidates from both parties have flooded into the race to replace retiring GOP Rep. Mark Amodei.

Two high-profile Republican representatives, Nancy Mace and Ralph Norman, have opted to give up their seats in the House to run for governor in South Carolina. Despite their national profiles, neither Mace nor Norman has been able to establish themself as the clear frontrunner in the race. Polls show them in a tight four-way contest with South Carolina Attorney General Alan Wilson and Lt. Gov. Pamela Evette.

Rep. Barry Moore and former Navy SEAL Jared Hudson are facing off head-to-head in a runoff for the GOP nomination after both defeating Alabama Attorney General Steve Marshall in the first round of voting. Moore and Hudson are both staunch Trump supporters who centered their campaigns around their MAGA credentials. Moore secured Trump’s nomination earlier this year, which helped him secure 39% of the vote in the first round, 14 points higher than Hudson’s tally. The winner of the runoff will be the overwhelming favorite to replace outgoing incumbent Tommy Tuberville, who’s on track to become Alabama’s next governor, in the Senate.

In Georgia, Republicans are holding runoffs to choose their candidates in two of the most important midterm races anywhere in the country. Rep. Mike Collins and former football coach Derek Dooley face off in a key Senate runoff, with the winner moving on to face Democratic incumbent Sen. Jon Ossoff. Ossoff’s seat is one of the GOP’s few opportunities to flip a spot in the Senate in a year in which they will mostly be playing defense across the rest of the country.

The GOP also has a runoff in the gubernatorial race, with billionaire Rick Jackson taking on the state’s current Lt. Gov. Burt Jones in a classic outsider-versus-establishment matchup. Jackson has contributed $83 million of his own money to his campaign and blanketed the state in political ads. But Jones has Trump’s endorsement, which helped him come out on top in the first round of voting. The runoff winner will go on to face Keisha Lance Bottoms, who is seeking to become Georgia’s first Democratic governor in more than two decades.

Oklahoma’s Senate race suddenly got interesting in March when Trump tapped incumbent Republican Markwayne Mullin to become homeland security secretary. Oklahoma’s governor named Alan Armstrong, the CEO of an oil and gas company, as Mullin’s replacement. Under a unique state law, Armstrong is not eligible to run for a full term in November. Five Republicans have joined the GOP primary, which will essentially decide who ends up being the deep red state’s next senator.

Maryland Democrat Steny Hoyer set off a mad scramble in January when he announced that he’d be giving up the House seat he’s held for the past 45 years. More than 20 candidates have entered the Democratic primary in his deep blue district. Democrats are also locked in another primary in Maryland’s Sixth District, where former Rep. David Trone is trying to regain the seat that he gave up in 2024 to launch an unsuccessful Senate bid. To do that, he’ll have to oust incumbent Rep. April McClain Delaney in the primary. Trone, the co-owner of the Total Wine & More retail chain, has a massive self-funding advantage, but McClain Delaney has secured the endorsements of most of Maryland’s high-profile elected officials.

There’s plenty of intrigue across the primaries for New York’s 26 House districts, but the race with the most national interest is in the state’s 10th District. Incumbent Democrat Dan Goldman, a relative moderate in the party, is facing a challenge from his left by former New York City Comptroller Brad Lander. Lander, who ran for mayor in the city last year, gained a strong support base among young voters for the way he embraced eventual winner Zohran Mamdani after suspending his own campaign.

Utah is using a completely new congressional map this cycle after court rulings that found that its old, Republican-drawn map violated state law. Now, instead of four safe GOP seats, Utah has one Democratic-leaning district, which four Democrats are competing in the primary for, and three red districts — but four incumbent Republicans. Rep. Burgess Owens ended up being the odd man out, and he announced in March that he wouldn’t seek another term. His exit means that none of the other incumbents will have to face each other in the primary, but at least two of them have fielded challenges from other GOP candidates.

The biggest headline in Louisiana’s Senate race happened in the first round of voting when incumbent Republican Sen. Bill Cassidy, one of the few remaining GOP lawmakers on Capitol Hill who voted to impeach Trump after the Jan. 6 attack, failed to reach the runoff in his bid for reelection. Instead, either Rep. Julia Letlow or State Treasurer John Fleming will be the Republican nominee and become the strong favorite to replace Cassidy in the Senate. Letlow, who was endorsed by Trump, came close to winning the primary outright in the first round with 45% of the vote.

Two Republican congressmen, Reps. Andy Biggs and David Schweikert, have entered the GOP gubernatorial primary for the chance to challenge Democratic Gov. Katie Hobbs in the general election. Their decision to potentially give up their seats in the House has prompted a number of Republicans to launch campaigns to become their replacements.

Kansas Gov. Laura Kelly is the rare Democrat who has enjoyed consistent electoral success in an otherwise strongly red state. After leading Kansas for eight years, Kelly is not eligible to run for reelection. Two state lawmakers, Ethan Corson and Cindy Holscher, are running to succeed her at the top of the Democratic ticket. Meanwhile, six Republicans are vying for the chance to turn the Kansas Statehouse red, including the state’s Senate president, the secretary of state and former Gov. Jeff Colyer.

Michigan Democrats will be playing defense in two of the most pivotal elections in this year’s midterms. The race to replace popular Democratic Gov. Gretchen Whitmer, who is term-limited, seems to be all but settled. Michigan Secretary of State Jocelyn Benson appears to have a clear path through the Democratic primary, and Rep. John James looks primed to secure the GOP nomination. Things are much tighter in the Democratic Senate primary, where state Sen. Mallory McMorrow, Rep. Haley Stevens and physician Abdul El-Sayed are locked in a close three-way contest. The winner of the Democratic primary is likely to face Republican Mike Rogers, who was 19,000 votes away from being elected to the Senate in 2024.

Missouri’s First Congressional District will feature a rematch of one of the most-watched primaries from the 2024 election. Former Rep. Cori Bush, a progressive member of “the Squad,” is challenging Rep. Wesley Bell, a moderate who defeated her in the Democratic primary last cycle. Their matchup two years ago was the second-most expensive House primary race in history, due to the $8 million that a pro-Israel group spent to target Bush.

Virginia’s congressional races have been subjected to severe whiplash in the past month, after a court ruling overturned a voter-approved ballot measure tied to a district map that favored Democrats. Primary races for seats under the previous district lines are still taking shape.

Democratic Rep. John Larson of Connecticut is seeking a 14th term in the House, but he’s facing his first serious primary challenge since first winning his seat in 1998. Three other Democrats have entered the primary, with each arguing that it’s time for Larson, 77, to allow a new generation to lead the district.

Minnesota is on track to have an enormous amount of turnover in its most important elected offices. With Gov. Tim Walz not seeking reelection, Sen. Amy Klobuchar has chosen to leave the Senate to pursue the chance to replace him. At least eight Republicans, including MyPillow CEO Mike Lindell, have joined a wide-open GOP gubernatorial primary. Klobuchar would potentially be in a position to name her own temporary replacement if she becomes governor. Minnesota’s other Senate seat is open this year because Democrat Tina Smith is retiring. Lt. Gov. Peggy Flanagan and Rep. Angie Craig are the main candidates in the Democratic Senate primary. Former sports broadcaster Michele Tafoya is the frontrunner for the GOP nomination.

Vermont’s gubernatorial race hinges on whether current Republican Gov. Phil Scott, who was recently declared the most popular governor in America, decides to run for another term. If he does seek reelection, he would be a strong favorite to win. If he doesn’t, the GOP would have to scramble to find a suitable replacement who can compete in the otherwise solidly blue state.

In Wisconsin, Democratic Gov. Tony Evers has chosen not to seek another term. Seven high-profile Democrats, including former Lt. Gov. Mandela Barnes and state Rep. Francesca Hong, have entered the race to replace him. That’s a stark contrast to the Republican primary, where Rep. Tom Tiffany looks like he’ll coast to his party’s nomination.

Alaska’s unique nonpartisan “jungle” primary system means that the four highest-ranking candidates in its Senate and gubernatorial races will move on to the general election, which will be decided by a ranked-choice vote.

Florida will elect a new governor this year. Rep. Byron Donalds, a strong Trump ally, is the overwhelming favorite to win the GOP nomination. Democrats haven’t won a governor’s race in Florida since 1994, but one March poll showed Donalds leading the two main Democratic candidates — Orange County Mayor Jerry Demings and former GOP Rep. David Jolly — by single digits. It’s a similar story in the Florida Senate race: Incumbent Republican Ashley Moody was outpacing potential opponents in the crowded Democratic field by roughly 8 points.

Progressive Democrat Ed Markey, 79, is running for another term in the Senate. He’s being challenged by Rep. Seth Moulton. Despite age being a major issue throughout the Democratic electorate, polls show Markey holding a solid — though not insurmountable — lead over his 47-year-old primary opponent.

Democratic Sen. Jeanne Shaheen is not running for reelection. Rep. Chris Pappas has a huge lead in polls of the Democratic Senate primary. Republicans have recruited two former senators in their effort to flip Shaheen’s seat. Polls show John E. Sununu, who Shaheen knocked out of the Senate in 2008, with a healthy edge over former Massachusetts Sen. Scott Brown.

Rhode Island’s Democratic governor, Dan McKee, seems to be at serious risk of being knocked out of office by a member of his own party. With a disapproval rating among likely voters of 76%, he trails former corporate executive Helena Foulkes by a significant margin in recent polls.