In the Antelope Valley and Orange County this weekend, House Minority Leader Hakeem Jeffries is rallying Democrats who are volunteering and raising money for Congressional candidates George Whitesides and Derek Tran.

And in Riverside County on Sunday, House Majority Leader Mike Johnson will appear at an event with incumbent Rep. Ken Calvert, seeking to bolster Republican enthusiasm in one of the country’s most competitive Congressional districts.

With a little over three weeks until the Nov. 5 election, both top party leaders campaigning in Southern California on the same weekend underscores the state’s importance to the battle for control of the House of Representatives.

Democrats need to pick up four seats nationwide to regain control of the House next year. Republicans currently hold a razor-thin majority in the House and are defending 15 seats considered tossups. Five of those races are in California, where Republican House members are fighting costly and acrimonious reelection battles.

“California matters more than any other state in terms of determining who’s going to control the House next year,” said Erin Covey, the House editor for the nonpartisan Cook Political Report.

The visits follow former President Trump’s Saturday campaign stop at a Coachella Valley polo field, energizing California Republicans who’ve often been overlooked by GOP presidential candidates because the state remains a Democratic stronghold.

Those races are in Orange County’s 45th District, where Derek Tran is running against Rep. Michelle Steel (R-Seal Beach); Riverside County’s 41st District, where Will Rollins is running against Calvert (R-Corona); the Antelope Valley’s 27th District, where Whitesides is running against Rep. Mike Garcia (R-Santa Clarita); and the always-contested Central Valley, where Adam Gray and Rudy Salas are running against Reps. John Duarte (R-Modesto) and David Valadao (R-Hanford).

A sixth seat, the 47th District in coastal Orange County, is also a battleground. The seat has no incumbent candidate because Rep. Katie Porter (D-Irvine) launched a bid for the U.S. Senate, losing in the primary, rather than seeking reelection to the House.

State Sen. Dave Min is facing former Orange County GOP Chairman Scott Baugh in the 47th congressional district, a race that Cook describes as “lean Democratic.” Baugh is seeking a rematch of 2022, when he narrowly lost to Porter in a bruising and expensive campaign.

So many seats are in play in California this year in part because Republicans surpassed expectations in California in 2022, Covey said. She said Democrats running for Congress felt voters’ displeasure over how state leaders, who are all Democrats, had handled crime and other issues.

But Democrats are expected to have a stronger shot at these districts in a presidential year, when turnout is higher.

Jeffries spoke Saturday afternoon at a rock-the-vote event for Tran that featured Vietnamese performers. The 45th Congressional District, home to Little Saigon, has the largest population of people of Vietnamese descent outside of Vietnam, but has never had a Vietnamese American representative in Washington.