California’s Senate primary has put some of the most powerful figures in the Democratic Party on opposing sides in what is becoming one of the most closely monitored and unpredictable races of the 2024 cycle. 

Progressive Rep. Barbara Lee (D-Calif.) got a big boost this week after Rep. James Clyburn (D-S.C.), a prominent establishment Democrat on Capitol Hill, threw his support behind her, crossing an ideological divide. That came after a leading voice on the left, Rep. Pramila Jayapal (D-Wash.), also offered her support, merging top figures from the Congressional Black and Progressive Caucuses.

At the same time, another progressive, Rep. Katie Porter (D-Calif.), had already locked down Sen. Elizabeth Warren (D-Mass.), one of the most coveted endorsements in the Senate, while Speaker Nancy Pelosi (D-Calif.) offered her name brand legacy to Rep. Adam Schiff (D-Calif.).

The battle lines being drawn within the party’s top names underscores the significance of the race for retiring Sen. Dianne Feinstein’s (D-Calif.) seat — as well as the differing views on who’s best poised to fill it.

“Right now, it’s the endorsement primary,” said Sacramento-based Democratic strategist Steven Maviglio.

For candidates competing in a close contest, a high-profile backer comes with significant cachet. While such endorsements don’t always change voters’ minds, they can be helpful in distinguishing candidates with similar positions. 

Even among Lee’s allies in the lower chamber, both Clyburn and Jayapal are particularly notable. Clyburn became a household name after his endorsement of President Biden helped him win the Democratic presidential primary in 2020, and Jayapal has been the lead negotiator between the White House and progressives in Congress during Biden’s first term.

Both have also been known to support candidates of color. While Lee aligns more with many of Jayapal’s policy positions, Clyburn too has recently given his name to several liberal candidates who, if elected, can help round out the diversity of the party across the country. 

An adviser to Clyburn said that the South Carolina Democrat is close friends with Lee, a fellow CBC member, and that “she is California” in a nutshell. 

“She’s been there on the frontlines. I think she’s reflective of California and America that’s becoming browner,” the adviser said. 

“You can’t discount what that means for people who have not had what they believe to be representation from a life experiences standpoint,” the source added. 

Offering his support on Wednesday, Clyburn said Lee “stands by what she believes in, and she doesn’t back down.”

Jayapal, who like other liberal House allies, considers Lee a critical member of the Progressive Caucus, and noted how she could bring a unique perspective to the still overwhelmingly white Senate. Indeed, it wasn’t too long ago that Vice President Harris (D-Calif.) represented the state as a Black female senator, and many members of the Democratic caucus are seeing Lee as part of continuing that legacy.

“As a woman of color, I know representation matters,” Jayapal wrote in her endorsement. “I’m excited for Barbara to bring her voice and her lived experience as a Black woman to the chamber so all of us can have a seat at the table.”

Strategists say that Lee’s strong showing of support is also a nod to her legacy in the place where she’s built relationships over the years.

“She’s well-respected and well liked beyond her district here in the Bay Area,” said Tenoch Flores, a former spokesman for the California Democratic Party. “It makes sense that her endorsements would include prominent local officials as well as members of the Congressional Black Caucus.”

While Lee certainly received some good news this week, the March 5 primary is far enough away for new alliances to form — and for candidates to draw sharper contrasts for voters.

Some Democrats have pointed to Lee’s age of 76 as a factor when electing a replacement to Feinstein, 89, whose own age and ability to perform her job has been a major focus in recent weeks. 

That’s created an opening for Porter, 49, to distinguish herself as a newer choice. 

“Californians are hungry for change and different leadership in Washington,” said Lindsay Reilly, Porter’s campaign press secretary. She noted two public polls released on the race so far show Porter “either ahead or within the margin of error, and each shows her advancing to the top-two general election.”

“She continues to pick up endorsements from Democrats and progressive leaders across the state and country, like Elizabeth Warren, the Progressive Change Campaign Committee, Assemblywoman Buffy Wicks, and local leaders representing every pocket of California,” she added. “Katie Porter has real momentum in this race.”

For Porter, having one of the Senate’s most visible progressives on her side is a big coup. It also comes as fellow progressive Sen. Bernie Sanders (I-Vt.) has not yet endorsed in the race. 

California’s political leanings are for the most part liberal. And the Senate seat is all but certain to remain within Democratic control. But the state also has a unique “jungle primary” election system, where all candidates are placed on the same ballot and the top two who earn the most votes advance to the general election regardless of party.

With two notable progressives in the race, some left-wing Democrats have grumbled about potential vote-splintering and said that eventually they’ll have to coalesce around one candidate.

“We do not want to split the Democratic vote between three Democrats, and we certainly do not want to split the progressive vote between two good progressive candidates,” said Amar Shergill, chair of the California Democratic Party’s Progressive Caucus.

“I’m willing to, like everyone else, sort of play this out over the summer,” said Shergill, who’s backing Lee. “But by the end of the summer, going into the fall, there needs to be one progressive candidate, and there certainly can’t be three Democrats.”

As the third choice, and arguably the most well-recognized nationally, Schiff is seen as the most moderate Democrat in the race. He’s also become a hero of sorts to anti-Trump Democrats for his role in the former Republican president’s impeachment trial and in the House select committee investigating the insurrection on Jan. 6, 2021. 

“In California, Schiff’s greatest endorsement will come in the form of the vitriol he continues to elicit from Donald Trump,” said Flores, suggesting that the congressman may be able to pierce through the identity politics of the race that includes two female rivals. Schiff has amassed support from much of the California delegation, but arguably no officeholder comes close to the level of clout as Pelosi. 

Pelosi, who recently criticized calls for Feinstein to resign over her age, gave Schiff her public approval, bringing increased attention from the longtime lawmaker considered a political icon in California. 

The Pelosi endorsement may not have deterred Clyburn and fellow House heavyweights from weighing in for her side, but it did show the unpredictable nature of the contest. Pelosi and Clyburn are each known for often backing winners, and Warren has a powerful progressive brand at the national level. 

As Democrats dig into their respective camps, one of the biggest unknowns is whether Feinstein retires before 2024, which could scramble the race and give Gov. Gavin Newsom (D) the opportunity to appoint a Democrat to fill her spot. 

Calls have amplified particularly among progressives for Feinstein to resign, which started in earnest with Rep. Ro Khanna (D-Calif.), who represents Silicon Valley, and followed by Rep. Alexandria Ocasio-Cortez (D-N.Y.). The New York Times’ editorial board became the latest voice to approach the subject, saying she needed to step down if she couldn’t carry out her senatorial obligations.

“The more votes that Sen. Feinstein misses, the more obvious it becomes that she needs to step down, particularly now with the debt limit crisis upon us,” Shergill said. “And if that happens and Sen. Feinstein still hasn’t taken her seat, I don’t know how she can continue on as our senator.”