These Southern California House races are still undecided. See election results updates

A handful of U.S. House election races in Southern California and across the country remained undecided one week after Election Day.

Over the weekend, more ballots were counted in competitive House races, including one separated by 1 percentage point, in Los Angeles, Orange, Riverside and San Bernardino counties.

While Democrats hold every major statewide office and outnumber registered Republicans in California 2 to 1, there are pockets of strong support for Republican candidates in parts of Southern California. Adding to the uncertainty, several California Republicans are representing districts that President Biden won in 2020, making the region a wildcard player in the makeup of the U.S. House.

All 435 U.S. House seats are up for election in 2024. Entering Election Day, Republicans had 220 members to Democrats' 212. There were three vacancies.

Scroll to see results updated Monday morning.

Democrat Whitesides unseats incumbent Rep. Garcia

George Whitesides, the former CEO of Virgin Galactic, defeated Rep. Mike Garcia in close contest for district north of Los Angeles.

NBC News projected Whitesides as the winner Monday evening. Garcia conceded Monday and congratulated political newcomer.

Rep. Garcia won the seat in 2022 by 6 percentage points over Democrat Christy Smith and held on to advance from the March primary. Whitesides finished second in the primary and had 50.9-percent of the votes counted early Monday in one of five California districts that voted for Joe Biden in 2020. Garcia stood at 49.1 percent.

It's a district that favored Republican Brian Dahle by a slight margin over Gov. Gavin Newsom in the 2020 gubernatorial election.

Garcia, who served in the U.S. navy and U.S. Navy Reserve, was first elected in a special election in 2020. The special election was called after Democrat Katie Hill, who defeated a Republican in 2018, resigned due to a sex scandal. He won re-election over Smith in 2022, 53.2 percent to 46.8 percent.

Whitesides served as NASA chief of staff in the Obama Administration.

The district in northern Los Angeles County includes Santa Clarita, Lancaster, Palmdale and other high desert communities.

Republican Rep. Young Kim defends House seat

GOP Rep. Young Kim will returns for a third term after winning the district two years ago by 14 percentage points. NBC News projected Kim as the winner in her race against former fire captain and union president Joe Kerr last week.

Kim is one of three Korean American women who were the first elected to Congress in 2020, served the California Assembly for two years. Kerr was unsuccessful in his 2022 bid for a state Senate seat and the Orange County Board of Supervisors in 2018.

As of Monday, Kim had 55.9 percent of the vote to Kerr's 44.1 percent.

The district includes parts of Orange, San Bernardino and Riverside counties The communities of Aliso Viejo, Corona, Chino Hills, Lake Forest, Mission Viejo, Rancho Santa Margarita, Tustin and Villa Park in the 40th District.

President Biden won the district by a slim margin in 2020.

President Biden won the district by a slim margin in 2020. Registered Republicans outnumber Democrats in the district by a margin of 38 percent to 34 percent, as of September.

Republican Rep. Calvert stretches narrow lead

Republican Rep. Ken Calvert held a nearly 3-percentage point lead early Monday in the race for the Riverside County Congressional district.

The races is a rematch between the long-time representative and Democrat Will Rollins. The two were separated by less than 5 percentage points in the 2022 election.

Calvert is the longest-serving Republican in the California congressional delegation, having held his seat in this district east of Los Angeles since 1993. Rollins, a former federal prosecutor, gets another chance to unseat the incumbent in November.

Of note: Palm Springs has been added to this district since the last election.

The district also includes Menifee, Lake Elsinore, Rancho Mirage, most of Corona and Palm Desert.

GOP Rep. Steel leads in tight race for 45th House district

Republican Rep. Michelle Steel was leading Democrat Derek Tran -- 51.1 percent to 48.9 percent -- early Monday in Orange County's 45th Congressional District.

Steel easily advanced from the primary in her race against four Democrats, including second-place primary finisher Derek Tran, a veteran and civil rights attorney. Tran had only 16 percent of the vote to Steel's commanding 55 in the crowded primary.

This district supported Joe Biden for president in 2020, but voted for Republican John Cox over Gavin Newsom in the 2018 gubernatorial election. Registered Democrats outnumber Republicans, but Steel defeated a Democrat in 2020 before winning re-election in 2022.

District 45, which re-elected Steel with 52.4% of the vote in 2022, includes parts of Orange and Los Angeles counties. The district includes Garden Grove, Westminster, Buena Park and Artesia. Parts of Brea, Lakewood, Fullerton and Yorba Linda are in the district that's shaped like a C and wraps around Anaheim.

Democrat Min takes slim lead in House District 47

This once solidly Republican district that stretches from Huntington and Newport beaches on the Orange County coast and inland to Irvine is the only open House seat among California's most competitive races. The seat was vacated by Katie Porter, who was running for Senate, but did not advance from the March primary and is not seeking re-election.

Scott Baugh, who lost to Porter by less than 4 percentage points in 2022, and Democratic state Sen. Dave Min are in a tight race with Min holding a 1-percentage point lead early Monday.

Baugh won the primary with 32 percent of the vote. Min was second at just under 26 percent with the remaining votes divided among other candidates.

The district had been represented by Republicans from the time it was created until Porter defeated then-Rep. Mimi Walters in 2018.

Democrat Rep. Levin leading in defense of 49th District House seat

Democratic U.S. Rep. Mike Levin held 51.7 percent of the vote in his bid to defend his seat in this Southern California district that includes portions of Orange and San Diego counties. Republican Matt Gunderson, a car dealership owner who failed in a bid for state Senate in 2022, was at 48.3 percent.

Voters chose Levin in 2018 to replace longtime Republican Darrell Issa, who has since returned to Congress in a neighboring district. Levin has since been re-elected twice — by six points in 2020 and 5 points in 2022.

Cities in the district include Oceanside, Carlsbad, Encinitas and the southern Orange County communities of San Clemente, Dana Point, San Juan Capistrano, Laguna Niguel and Ladera Ranch.