Candidates in California’s volatile race for governor will meet Wednesday night for the first televised debate since Eric Swalwell dropped out, each looking to seize momentum in the tight contest.

The debate, being held at the television studio of KRON4 in San Francisco, will include four Democrats and two Republicans who are tightly bunched in recent polls, with many voters still undecided less than six weeks before the June 2 primary.

Mr. Swalwell, a Democrat, had just begun to emerge as a Democratic front-runner when his campaign swiftly collapsed after he was accused of sexual assault in news reports on April 10.

Candidates have taken relatively few risks so far in debates around the state, but every candidate is now eyeing a chance to jump to the front of the pack.

“Even though we have seen some movement in the last couple of weeks, it continues to be a fairly crowded, fractured field,” said Sara Sadhwani, an assistant professor of politics at Pomona College. “So candidates need to be able to grab attention in a debate like this.”

The debate comes as Xavier Becerra, a Democrat and former California attorney general, has enjoyed a surge of support in polls since Mr. Swalwell dropped out of the race.

Mr. Becerra and Matt Mahan, the mayor of San Jose, did not originally meet the threshold to participate in Wednesday’s debate when Mr. Swalwell was running. But they both qualified after receiving enough support in a follow-up poll that debate organizers commissioned once Mr. Swalwell had dropped out.

The other Democrats scheduled to participate are Tom Steyer, a former hedge fund manager, and Katie Porter, a former congresswoman, each of whom have been polling near the top of the Democratic field for several weeks. The Republicans in the debate are Steve Hilton, a former Fox News host who has been endorsed by President Trump, and Chad Bianco, the sheriff of Riverside County.

All candidates run on the same ballot in California’s nonpartisan primary, with the two who receive the most votes advancing to the general election, regardless of their party affiliation. The large number of Democratic candidates has created fear among state party leaders that their voters could splinter, potentially allowing two Republicans to sweep the primary in this heavily Democratic state.

The odds of that happening have decreased since Mr. Swalwell dropped out and another Democrat, Betty Yee, withdrew on Monday. But Rusty Hicks, the chairman of the California Democratic Party, still believes there are too many Democrats in the race and has urged those lagging in polls to end their campaigns. (The actual ballot will include 61 candidates for governor, most of whom are completely unknown to voters.)

The messy race to succeed Gov. Gavin Newsom, who cannot run for re-election because of term limits, has played out as the most unpredictable contest California has seen in a generation. It has attracted a sprawling field but no one with the star power of former Gov. Arnold Schwarzenegger or the political might of Mr. Newsom or former Gov. Jerry Brown.

Much of California’s Democratic establishment is still figuring out whom to back in the turbulent race.

Mr. Newsom has not endorsed anyone, saying he trusts voters to elect someone “who reflects the values and direction Californians believe in.” Representative Nancy Pelosi, the influential former House speaker from San Francisco, and Senator Alex Padilla also have not announced their favorites. Senator Adam Schiff endorsed Mr. Swalwell earlier this year but quickly withdrew his support after the accusations against him were published.

On Tuesday, Ms. Yee endorsed Mr. Steyer, praising his work to fight climate change and engage young voters. Mr. Steyer has swamped his competitors with a raft of advertising by pouring $134 million from his personal fortune into his campaign.

Also on Tuesday, Mr. Becerra, whose campaign had appeared to be flailing until Mr. Swalwell dropped out, received the endorsement of Robert Rivas, the Democratic speaker of the California State Assembly. Mr. Rivas said he had encouraged Mr. Becerra to run for governor because he was impressed by his work as California’s attorney general during President Trump’s first term.

“He understands both the policy and the politics,” Mr. Rivas said in an interview. “And he has a track record, in my opinion, of delivering results under pressure.”

The 90-minute debate on Wednesday begins at 7 p.m. PT and will be broadcast and streamed by KRON and other California stations.

Virginians approved a new congressional map on Tuesday that would aggressively gerrymander the state in the Democrats’ favor, giving the party as many as four more U.S. House seats.

The new map draws eight safely Democratic districts and two competitive districts that lean Democratic, according to a New York Times analysis of 2024 presidential results. It leaves just one safe Republican seat, compared with the five seats the G.O.P. holds on the current map.

The proposed map was drawn by Democratic state legislators and approved by Gov. Abigail Spanberger, a Democrat. It eliminates three Republican-held seats in part by slicing the densely populated suburbs in Arlington and Fairfax Counties and reallocating their overwhelmingly Democratic voters into five congressional districts, some stretching more than a hundred miles into Republican areas.

Perhaps the most extreme new district is the Seventh, which begins at the Potomac River and stretches to the west and south in a manner that resembles a pair of lobster claws. Several well-known Virginia Democrats have already announced their candidacies and begun campaigning in the district.

Reid J. Epstein contributed reporting.