Primaries in Oregon, Georgia, Kentucky and Idaho on Tuesday will decide general election matchups in a small handful of key House races, while voters in California will also pick the candidate to finish the rest of former Speaker Kevin McCarthy’s (R) term in the lower chamber. 

At the top of the ticket in Kentucky and Oregon, President Biden and former President Trump are set to rake in more delegates in their respective primaries, less than six months out from their Election Day rematch. Also in Oregon, two high-profile Democratic House primaries are pitting establishment-backed candidates against progressives in a test of the left’s strength.

Polls will close in the various states between 6 and 11 p.m. Eastern time. Here are six of the key races to watch: 

Oregon 5th District Democratic primary

Oregon’s 5th Congressional District flipped into Republican hands in the midterms, and Democrats this year are seeking to oust incumbent Rep. Lori Chavez-DeRemer (R) and snag back the seat, which could be among the key races that decide control of the House this fall.

The House Democrats’ national campaign arm has backed state Rep. Janelle Bynum (D) in a blow to Jamie McLeod-Skinner, who was the unsuccessful Democratic nominee in 2022 and is running again this year. 

McLeod-Skinner defeated then-Rep. Kurt Schrader (D-Ore.) — who had President Biden’s backing — in the midterm primary, but lost to Chavez-DeRemer by two points in the general. 

This time around, the party is hoping that Bynum, who has beaten Chavez-DeRemer before in two state legislature races, will have better luck. 

Strategists expect a close primary, as Bynum and McLeod-Skinner battle to take on the Republican incumbent. Extensive primary polling hasn’t been conducted, but an April survey paid for by Bynum’s campaign shows the state lawmaker with a slight lead in the district, which spans from Bend in central Oregon to Multnomah and Clackamas counties just outside of Portland.

Oregon 3rd District Democratic Primary

Oregon’s 3rd Congressional District seat is solidly blue, but the race has still drawn national attention as Democrats vie to succeed retiring Rep. Earl Blumenauer (D-Ore.), whose exit opens up the seat for the first time in nearly three decades. 

Among the top contenders for the seat is Multnomah County Commissioner Susheela Jayapal, the sister of U.S. Rep. Pramila Jayapal (D-Wa.). If she succeeds, the pair would become the second set of sisters to serve together in the lower chamber, after Loretta and Linda Sanchez made history as sister lawmakers from California. 

But state Rep. Maxine Dexter has given Jayapal a run for her money — literally, as she has raked in more than half a million dollars over the last quarter. Dexter’s primary rivals, including Jayapal, have said that some of that money is coming from a PAC tied to the American Israel Political Action Committee (AIPAC). And Jayapal’s allies have also asserted that Republican meddling has boosted Dexter.

“Republican megadonors have spent millions to defeat my sister ​​@SusheelaJayapal – all because she is a proud, effective progressive,” Pramila Jayapal said in an Instagram post. 

Regardless of who wins, Democrats are almost certain to keep the seat in their hands come November, making the contest primarily a test for the establishment and progressive wings of the party.

Progressive DA race in Portland

The progressive district attorney who took office in Oregon’s Multnomah County amid 2020 social justice protests in Portland faces a primary challenge from a competitor promising to be tougher on crime. 

District Attorney Mike Schmidt was elected in a landslide amid the COVID-19 pandemic and a push for criminal justice reforms. During demonstrations that roiled Portland in the wake of George Floyd’s death at the hands of police, he announced back in 2020 that his office wouldn’t go after many protestors who were arrested. 

But the Beaver State has since seen growing frustration over public safety amid drug decriminalization efforts, increasing homelessness.  

Schmidt is now being challenged by one of his own deputies, Nathan Vasquez, whose platform stresses that “[even] ‘petty’ crimes, like theft, vandalism, and littering, public use of illicit drugs and public highs, all contribute to the overall  feeling of safety and wellbeing of a community.”

Fani Willis primary challenge in Georgia

Fulton County District Attorney Fani Willis (D) is leading the prosecution of former President Trump in a case centered on efforts to interfere with Georgia’s 2020 election results. 

She’s also up for reelection and faces a primary challenge from attorney Christian Wise Smith, who ran and lost against Willis four years ago. 

It’s the first time Willis has gone before voters since launching her probe into Trump’s actions in the state. Revelations of a romantic relationship between Willis and one of Trump’s top prosecutors tripped up the proceedings for weeks, but Willis was allowed to remain in her role. 

Willis is generally expected to prevail on Tuesday. With that said, if Smith were to score an upset, it could have notable ramifications on the high-profile case. Asked earlier this year whether he would continue pursuing Willis’s case against Trump, Smith said “that issue is important to us here in Fulton County and a lot of people across the country.”

The winner of the Democratic primary is set to go against Republican candidate Courtney Kramer, an attorney who worked in the Office of the White House Counsel under Trump, in the fall.

Georgia state Superior Court, Supreme Court races

Another key player in Trump’s Georgia case is up for reelection this year: Fulton County Superior Court Judge Scott McAffee.

A former prosecutor who was appointed to the bench by Republican Gov. Brian Kemp back in 2022, McAffee faces challenger Robert Patillo in the contest. If McAffee loses, his caseload could go to his successor. 

Meanwhile, Democratic former Rep. John Barrow (D-Ga.) is hoping to flip a state Supreme Court race in a contest that has played out against the backdrop of the Peach State’s six-week ban. Barrow is running against state Supreme Court Justice Andrew Pinson, a Kemp appointee who once clerked for Supreme Court Justice Clarence Thomas. 

The Democrat believes the procedure is a right, while Pinson has argued the former lawmaker is “running a hyper-partisan campaign.” 

Special election to fill McCarthy’s seat in California 

Voters in California on Tuesday will weigh in on a special election to fill former Speaker Kevin McCarthy’s (R-Calif.) reliably red seat in the Golden State’s 20th District. 

McCarthy announced plans to leave the lower chamber after his historic removal ended a brief tenure in the top House role. He wrote in a Wall Street Journal op-ed that he was stepping out of the House “to serve America in new ways. I know my work is only getting started.”

Now, County Sheriff Mike Boudreaux (R) will face off on Tuesday against Republican state legislator Vince Fong in a runoff to claim McCarthy’s seat for the remainder of his term – and then the pair will battle again to win a full term in November. 

Trump and McCarthy both have put their weight behind Fong, positioning him the favorite to win the seat.