LOS ANGELES (AP) — California is one of the most heavily Democratic states in the country, but Republicans this year are determined to regain a string of U.S. House seats that they lost to Democrats two years ago.

President Donald Trump, who wants the House back under GOP control and House Speaker Nancy Pelosi demoted, has said that with hard work, Republicans “can pick up seven seats in the state of California.”

Tuesday’s primary election will set the stage for those November battles, which will play out in a state that is home to the so-called Trump resistance and where the president is widely unpopular outside his core GOP base.

Republicans hold a mere six of the state’s 53 House seats, with two vacancies. But the party wants to show it can bounce back, even in a state where Democrats control every statewide office, dominate both chambers of the Legislature and hold a 4.3-million edge in voter registrations.

The seven races in districts won by Democrats in 2018:

10TH CONGRESSIONAL DISTRICT

Democratic Rep. Josh Harder and Republican Ted Howze, a veterinarian, were in a close race as they separated from the remainder of the field. Harder, a venture capitalist, grabbed this farm belt seat from Republican Jeff Denham in 2018. Democrats hold a registration edge in the district, though the state's agricultural centers have long been known for Republicans who vote reliably and Democrats who often do not. Other candidates lagged further back.

21ST CONGRESSIONAL DISTRICT

Trump recently called former Republican Rep. David Valadao “an incredible guy” he wants back in Washington. But to get there, he’ll need to defeat the Democrat who narrowly beat him in 2018, Rep. TJ Cox. The district has a deceptively large Democratic registration edge — Valadao held the seat for several terms before Cox’s 2018 victory. They are among four candidates on the ballot. A tally of early votes showed the pair far ahead of two other candidates, setting up a potential rematch.

25TH CONGRESSIONAL DISTRICT

This swing district north of Los Angeles is vacant after Democratic Rep. Katie Hill resigned amid a sex scandal and House ethics probe last year. Democratic legislator Christy Smith and former combat pilot and defense industry executive Mike Garcia were leading a crowded field in early returns in both a special election to finish the remainder of Hill's term and a primary for the term that begins in 2021. Other candidates in the mix include online news personality and progressive Cenk Uygur; former Republican Rep. Steve Knight, who lost the seat to Hill in 2018; and former Trump campaign aide George Papadopoulos, who served a two-week prison sentence for lying to the FBI about his interactions with Russian intermediaries during the 2016 campaign.

39TH CONGRESSIONAL DISTRICT

Voters in the closely divided, diverse district anchored in Orange County will see a rematch between first-term Democratic Rep. Gil Cisneros and Republican Young Kim. Cisneros claimed the seat in 2018, one of four Republican-held districts all or partly in Orange County that Democrats won. It was a stunning realignment in a county once known as a national GOP stronghold. Kim and Cisneros easily outpaced independent Steve Cox.

45TH CONGRESSIONAL DISTRICT

Several Republicans who hope to face off against Democratic Rep. Katie Porter were closely bunched in early votes. Two years ago, Porter proved that even a progressive can win in the heart of what was once California’s “Reagan country” in a district with a Republican tilt. The law professor and protégé of presidential candidate Elizabeth Warren snatched the Orange County seat in 2018 from Republican Rep. Mimi Walters. This time, Porter is the sole Democrat on the ballot and a handful of Republicans are dueling for a chance to challenge her, including former fighter pilot Greg Raths, Laguna Hills City Councilman Don Sedgwick, Yorba Linda Councilwoman Peggy Huang and Lisa Sparks, dean of Chapman University’s School of Communications.

48TH CONGRESSIONAL DISTRICT

A tally of early votes showed Democrat Harley Rouda closely matched with Republican Michelle Steel, who heads the Orange County Board of Supervisors. Two years ago, Rouda ousted long-serving Republican Rep. Dana Rohrabacher from the coastal district, which includes Newport Beach and other wealthy enclaves. The district retains a Republican registration edge, but Rouda exposed its shifting politics with his surprise win in 2018.

49TH CONGRESSIONAL DISTRICT

First-term Rep. Mike Levin is defending his seat against Republican Brian Maryott, the only candidates on the ballot. The district anchored in San Diego County has a small Republican registration edge but has been growing increasingly favorable for Democrats for years. Levin carried the district by nearly 13 points in 2018.