Who will replace Dianne Feinstein in the Senate? Gov. Newsom will pick

As California’s political class on Friday mourns the death of Democratic Sen. Dianne Feinstein, it is also privately buzzing about what happens to her now-vacant Senate seat.

Feinstein had already announced she would not run for re-election in 2024, triggering a competitive election to select a successor. Now, her death will force Democratic Gov. Gavin Newsom to appoint a replacement to serve out the remainder of the term — a politically fraught decision he has been dreading having to make.

An appointment could upend California’s blockbuster Senate primary, which pits high-profile Democratic Reps. Adam Schiff, Katie Porter and Barbara Lee against each other ahead of an all-party primary in March.

With a looming government shutdown, Newsom may feel pressure to name a replacement quickly to give Democrats an additional vote to pass spending legislation.

Senate Majority Leader Chuck Schumer, D-N.Y., spoke with Newsom on Friday, a spokesperson for the senator said. The call comes as the Senate waits for Newsom to fill the vacancy that’s left Democrats with a 50-49 majority.

A source close to Newsom told NBC News he will announce an interim appointment for Feinstein's seat in the coming days.

Newsom has for months been open about the fact that he does not want to choose a replacement for Feinstein, especially since he already appointed the state’s other senator, Democrat Alex Padilla, when Kamala Harris vacated her former Senate seat to accept the vice presidency in 2020.

Newsom faced backlash over the decision to replace Harris, the only Black woman in the Senate, with Padilla, a Latino man, so the governor pledged that he would select a Black woman to fill any future vacancies.

That pledge was widely seen as a nod to Lee, and Newsom advisers have said he likely would have chosen her if Feinstein had earlier heeded calls to resign as her health declined several years ago.

But Newsom made that pledge more than two years ago, well before Feinstein announced she would not run for re-election and before anyone entered the race to replace her.

And earlier this month, Newsom said on NBC News’ "Meet the Press" that he would instead make an “interim appointment” — someone expected only to serve out the remainder of the term and not seek election to another full term. He suggested that person would still be a Black woman, though.

“I don’t want to get involved in the primary,” Newsom explained. “It would be completely unfair to the Democrats that have worked their tail off. That primary is just a matter of months away. I don’t want to tip the balance of that.”

Newsom's announcement incensed Lee, who issued a rare public rebuke of her fellow Democrat, saying on cable news appearances and a news release that a temporary appointment of a Black woman to the Senate seat would be mere tokenism.

“I am troubled by the governor’s remarks,” Lee said in a statement. “The idea that a Black woman should be appointed only as a caretaker to simply check a box is insulting to countless Black women across this country who have carried the Democratic Party to victory election after election.”

“The perspective of Black women in the U.S. Senate is sorely needed — and needed for more than a few months. Governor Newsom knows this, which is why he made the pledge in the first place,” Lee continued. “If the Governor intends to keep his promise and appoint a Black woman to the Senate, the people of California deserve the best possible person for that job. Not a token appointment.”

Lee’s broadside surprised many California politicos — including her allies running a super PAC supporting her campaign.

Two well-known California Democratic operatives quit the super PAC over Lee's criticism of Newsom, since both were also his advisers and felt they had to pick sides, people familiar with their thinking confirmed to NBC News after Politico first reported their departure.

Schiff and Porter are well ahead of Lee in polling and fundraising, so an appointment is widely seen as Lee's best shot at winning the Senate seat.

Allies of Schiff and Porter, naturally, say it would be completely unfair for the governor to elevate the candidate polling in third place before voters have a chance to weigh in.

Newsom has complained that the lobbying over Feinstein's seat has been constant and inescapable. “Emails, calls, texts, people stopping me. I’m not kidding,” Newsom said earlier this year. “This is one of the biggest topics here, and it was one of the biggest topics when I was in Alabama, even Jackson, Mississippi.”

Regardless of whom Newsom appoints, under California's "jungle primary" system, the two leading candidates of any party in the March primary will advance to the general election, meaning two Democrats may face off in November, given the state's liberal lean.

Moreover, any Newsom appointment could trigger a new round of political musical chairs in California, where open Senate seats are an extreme rarity.

Already, candidates are competing for the House seats left behind by Schiff, Porter and Lee when they mounted their Senate bids — Porter’s is a particularly competitive district — and appointing them or any elected Democrat to Feinstein's seat could open more vacancies that would also need to be filled.

Some names of Black women who have been floated include California Secretary of State Shirley Weber (who replaced Padilla in that job), San Francisco Mayor London Breed, Los Angeles County Supervisor Holly Mitchell, and nonprofit executive Lateefah Simon, who is currently running for Lee’s House seat.

Newsom could also choose someone not currently holding elected office, with names floated like former Govs. Jerry Brown and Arnold Schwarzenegger, or former Sen. Barbara Boxer, but those bold-faced names would not fulfill Newsom's pledge to appoint a Black woman, if he decides to stick to it.

So far, however, people close to the governor and the candidates are not eager to discuss political fallout of Feinstein's death, instead saying they are focused on honoring her legacy — for now.

"There is simply nobody who possessed the strength, gravitas, and fierceness of Dianne Feinstein," Newsom said in a statement Friday. "Jennifer and I are deeply saddened by her passing, and we will mourn with her family in this difficult time."

CLARIFICATION (Oct. 5, 2023, 9:40 a.m. ET): According to her office this week, Sen. Dianne Feinstein died early on Friday, Sept. 29. A previous version of this article, citing her office, said in a photo caption that she had died the day before, Thursday, Sept. 28. The article has been updated.

This article was originally published on NBCNews.com