Five states hold polls on Tuesday. Here's what to know.

A man walks outside Lincoln Liquor & Wine on Monday in Oak Park, Mich. The highly contested Democratic primary for U.S. Senate is bringing national attention to Michigan ahead of voting on Tuesday. Finn Gomez/Getty Images hide caption

Five states hold primaries Tuesday, with competitive House and Senate races that could ultimately decide control of Congress next year.

Kansas, Michigan, Missouri, Virginia and Washington are all holding contests. A number of Democratic primaries are pitting congressional incumbents against progressive challengers.

Redistricting efforts will also influence the races. Missouri Republicans redrew their map to squeeze Democrats, while Virginia moved its primary from June to August for a Democratic redistricting push that courts ultimately threw out .

Democrats choose between moderates and progressives

The open U.S. Senate seat in Michigan, a swing state, has two Democratic candidates lodged in a tight race to win their party's nomination.

Democratic U.S. Senate candidate Abdul El-Sayed speaks at his Get Out the Vote rally in Detroit on Monday. He is hoping to defeat U.S. Rep. Haley Stevens in the Democratic primary to advance to the general election in November. The candidates are vying to replace retiring Sen. Gary Peters. Jeff Kowalsky/AFP via Getty Images hide caption

Abdul El-Sayed, a progressive candidate supported by other far left-leaning Democrats will be up against Rep. Haley Stevens, a more moderate candidate, supported by Democratic Party leaders. El-Sayed is a former Detroit public health official who ran an unsuccessful bid for governor in 2018.

U.S. Rep. Haley Stevens, D-Mich., a candidate for Michigan's open U.S. Senate seat, speaks to the press before talking to churchgoers at Fellowship Chapel on Sunday in Detroit. Abdul El-Sayed, an epidemiologist, currently holds a double-digit lead against Stevens, a four-term congresswoman, according to recent polling. Finn Gomez/Getty Images hide caption

Stevens is running for a fifth term and has been boosted by millions in outside spending. She has outspent El-Sayed on the airwaves by at least eight times, according to AdImpact — including groups aligned with the American Israel Public Affairs Committee, a pro-Israel lobbying group, whose involvement El-Sayed has criticized.

El-Sayed is leading the polls for the primary contest. Yet Haley supporters argue that she has a better chance of winning in a purple state in November's general election. Whoever wins the Democratic nomination will face Mike Rogers, a former congressman who is unopposed for the Republican nomination and narrowly lost the state's other U.S. Senate seat to Sen. Elissa Slotkin in 2024.

If the Democrats want to win back the Senate, they have to hold on to the seat in Michigan. The race has also garnered national attention because it's become a referendum on the Democratic Party's identity and the kind of candidate it should be nominating: a centrist or someone more left leaning.

Tuesday's contests will decide several competitive U.S. House primaries

Another test of the Democratic Party's direction will be in Michigan's 13th House District, which covers most of Detroit. Democratic Rep. Shri Thanedar, the multimillionaire businessman, is running against state Rep. Donavan McKinney , a progressive Detroit native. McKinney has the endorsement of Sen. Bernie Sanders and Rep. Rashida Tlaib and has made Thanedar's wealth and corporate ties the center of his more left-leaning campaign.

Republicans are fielding a handful of low-profile candidates, but according to Cook Political Report , whoever wins the Democratic primary is heavily favored in November.

In Washington's conservative 4th Congressional District, rated as solidly Republican by Cook Political Report, the top three Republican candidates are representative of three different arms of the party .

Amanda McKinney, the Yakima County commissioner, has an endorsement from President Trump. Businessman and former candidate Jerrod Sessler has campaigned as the anti-establishment outsider. Republican state Sen. Matt Boehnke is more moderate.

Tuesday's decision by GOP voters will reflect the direction they have chosen for a rural, heavily Latino district that subsists on agriculture and energy production.

In Missouri, the solid blue 1st Congressional District that includes St. Louis is hosting another one of this cycle's marquee Democratic primaries on Tuesday: between current Congressman Wesley Bell and former Congresswoman Cori Bush.

Bell defeated Bush two years ago, and now they are both back for a fiery rematch. Whoever wins this race — where apart from local issues, military aid to Israel has also been a big point of contention — will likely go on to serve in Congress.

While Bush has said she would vote to cut off military aid for Israel, Bell has voted against those moves. Bell is backed by Democrats like House Minority Leader Hakeem Jeffries and former House Speaker Nancy Pelosi, while Bush is supported by the Democratic Socialists of America.

Seven other congressional districts in Missouri will hold primary races to pick candidates Aug. 4, under a new map the Republican-led Legislature passed that reshaped Democratic Rep. Emanuel Cleaver II's Kansas City-area seat.

Primary wins that could shape November

Back in Michigan, a governor's seat is in play because term-limited Democratic Gov. Gretchen Whitmer is leaving it open in a state President Trump carried in 2024.

Tuesday's margins and turnout will offer the first signals about Democratic and Republican enthusiasm heading into November. The Democratic front-runner is Jocelyn Benson, Michigan's secretary of state since 2019, according to the Cook Political Report.

Benson's priorities are the economy and the public education system, she told Michigan Public Radio , while her competitor, Chris Swanson, the current Genesee County sheriff, said he would focus on an audit of the state women's prison, on curbing energy price hikes and on giving Epstein victims a voice.

Republican gubernatorial candidate John James speaks to attendees during a Macomb County primary eve party at Bumpers Landing on Monday in Harrison Township, Mich. James faces businessman Perry Johnson in Michigan's Republican primary on Tuesday. Finn Gomez/Getty Images hide caption

In the Republican primary, Congressman John James, the 2018 and 2020 Senate nominee, has Trump's endorsement, though Perry Johnson, a businessman and author, is proving to be tough competition. Johnson's priorities include eliminating the state income tax, making property taxes less onerous and improving the quality of the state's education programs, he told Michigan Public Radio .

Republican gubernatorial primary candidate Perry Johnson speaks with voters on July 20 in Port Huron, Mich. Paul Sancya/AP hide caption

The House majority is likely to come down to a handful of tossups, including Michigan's 7th Congressional District, where Republican Rep. Tom Barrett will run against the Democratic nominee who wins Tuesday's primary.

Other races to know

Virginia's Election Day was pushed from June to August this cycle after a congressional redistricting referendum and an effort to change the maps by the Democrats; the attempt was overturned by the Virginia Supreme Court on technical grounds, but the later date stayed in place.

Michelle Moffit, a director at Virginia Civic Engagement Table, a non-partisan, non-profit that works to protect voting rights, said she expects more participation from voters because of the Louisiana v. Callais decision and how it could have impacted Virginia.

"I think more people are aware of what's at stake and how precious the right to vote is," she said.

Voters will pick nominees for the U.S. Senate and the U.S. House on Tuesday, including in a few competitive swing districts in Virginia that could help decide control of the narrowly divided chamber in November.

A crowd of Democratic candidates are competing in a primary in Kansas on Tuesday for a Senate seat, according to Kansas Public Radio . The winner will challenge Republican incumbent Roger Marshall in November.

Kansas' gubernatorial and House races also have contests between establishment candidates and outside challengers, to match the national trend, in both Republican and Democratic primaries.