It's 8 p.m. Eastern, and polls just closed in Missouri as well as in most of Michigan and Kansas. (Polls close in an hour in parts of Michigan's Upper Peninsula and a handful of western counties in Kansas.)

We're tracking about a dozen key races in those three states, so results may start coming fast and furious between now and 11 p.m. Eastern, when the last polls close in Washington state. Watch this space!

—Tia Yang, 538

A crowded primary emerged in eastern Washington's 5th District, after Republican Rep. Cathy McMorris Rodgers opted not to seek reelection. Six Republicans and five Democrats are running, including Spokane County Treasurer and former state Sen. Michael Baumgartner, a Republican who is leading the pack in fundraising. As of mid-July, Baumgartner had raised over $790,000, more than double the next highest fundraiser, Republican state Rep. Jacquelin Maycumber. At a debate in June, Baumgartner was one of the few Republicans on stage who said he believed Biden legitimately won in 2020, while Maycumber said she had "grave concerns" about the 2020 results.

With McMorris Rodgers retiring relatively late (she made her announcement in February), there hasn't been much time for candidates to build funds or momentum, meaning other than Baumgartner's financial edge, it's hard to identify a frontrunner in the race. In this red-leaning district, which gave Trump 53 percent of the vote in 2020, there's a chance two GOP candidates could advance to the general election, although there are a few credible Democrats running too, such as former State Department officer Carmela Conroy and gynecologist Bernadine Bank.

—Kaleigh Rogers, 538

In the solidly red 4th District in central Washington, Republican Rep. Dan Newhouse once again finds himself fighting for his political life. Of the 10 House Republicans who voted to impeach Trump after the events of Jan. 6, Newhouse was one of only two who managed to secure another term in the 2022 election. This time around, Newhouse has two major GOP opponents in former NASCAR driver Jerrold Sessler, who finished behind Newhouse two years ago and initially received Trump's sole endorsement for this race, and veterans advocate Tiffany Smiley, the party's 2022 Senate nominee (who lost to Sen. Patty Murray). Until Sunday, it more or less appeared that Newhouse was the least pro-Trump candidate, Sessler the most and Smiley somewhere in between. But then Trump further muddled things by also endorsing Smiley, making this yet another primary where he's backed multiple candidates. If Smiley gains at Sessler's expense, that could have major ramifications for who makes it to the general election: Unlike in 2022, local Democrats haven't coalesced around one candidate, making it more likely that two Republicans could advance out of the top-two primary.

Newhouse does have a financial advantage, having raised almost $1.6 million, more than Smiley ($720,000) and Sessler ($409,000) combined. But pro-Smiley groups have spent $539,000 supporting her or attacking the other two Republicans, while pro-Newhouse outfits have invested $190,000. With an eye on winning over conservatives considering Smiley, Newhouse's campaign has attacked her for supposedly deceiving GOP donors by creating a political action committee ostensibly aimed at raising money for Republican candidates but that the Seattle Times found had mostly worked to retire Smiley's 2022 campaign debt. Newhouse also promoted his efforts to protect Washington farm land from purchase by "Communist China." For her part, Smiley has emphasized her outsider credentials, attacked Newhouse for voting to impeach Trump and claimed that Sessler would like to tax beef. Sessler has understandably played up Trump's support for his campaign as well as his endorsements from the far-right House Freedom Caucus and the state GOP.

—Geoffrey Skelley, 538

Candidates of color are running in primaries across all four states tonight in both parties, although a majority of them are Democrats. They include groundbreakers, surprise winners from the last election and longshot candidates.

In Kansas, Rep. Sharice Davids, who in 2018 became the first openly LGBTQ+ member of Congress from Kansas and one of the first two Native American women ever elected to Congress, is running unopposed in her Democratic primary, but she'll find out who her opponent is this fall. The frontrunner is Dr. Prasanth Reddy, an Indian-American who immigrated with his family to Kansas as a child. Davids is a top target for the GOP in November and could have a tough time keeping her seat.

Criticism over the Israel-Hamas war is shaping up to be a decisive issue in many primaries. In Michigan, incumbent and "Squad"-member Rep. Rashida Tlaib, the first Palestinian-American to serve in Congress and a vocal critic of the Biden administration's approach to the Israel-Hamas war, is running unopposed in the 12th District seat. But next door in the 11th District, Ahmed Ghanim, an Egyptian-American who has called for a cease-fire, is making a long-shot bid to challenge incumbent Democratic Rep. Haley Stevens. Stevens won against another incumbent and Israel critic, former Rep. Andy Levin, on a pro-Israel platfrom after redistricting forced them to face off in 2022.

Unlike Tlaib, Rep. Cori Bush, a fellow "Squad" member and outspoken critic of Israel's war in Gaza, is facing a serious challenge today. In one of today's most contentious races, Bush has two Black challengers for the Democratic nomination, including St. Louis County prosecutor Wesley Bell, who's notably been backed by pro-Israel super PACs.

Meanwhile, both party's primaries for the critical Michigan Senate race include a candidate of color, though both are seen as long shots to win their respective contests today: Former Rep. Justin Amash, a Syrian- and Palestinian-American and a vocal Trump critic who previously left the Republican Party, is running for the Republican nomination for Senate, while actor Hill Harper, who is Black, is running for the Democratic nomination.

It's a similar situation in Missouri's governor race, where two Black Democrats and one Black Republican are running for the chance to be their parties' nominees, though the state's Republican Secretary of State, Jay Ashcroft, and Lt. Gov. Mike Kehoe are favorites to win the Republican primary. The winner will likely go on to win the general election in the safe red state.

Candidates of color are running for many positions across the state in Washington. Notable ones include Rep. Marie Gluesenkamp Perez, a Hispanic candidate who unexpectedly won against Republican Joe Kent in the state's 3rd District in 2022 and will face Kent once again this year. The crowded field in the open race for the state's governor also includes four Black Democrats and one Black Republican, but the frontrunner appears to be state Attorney General Bob Ferguson, who is white.

—Monica Potts, 538