The 2024 California Senate race could be Democrats' next big civil war

California may be America's most populous and progressive state. Yet it hasn't enjoyed — or endured, depending on your appetite for political drama — a truly competitive U.S. Senate election in more than 30 years.

Until now.

With the news Thursday that Rep. Adam Schiff of Los Angeles is entering the ever-more-crowded fray — and that 89-year-old incumbent Sen. Dianne Feinstein isn't even planning to decide whether to retire or run again until "next year" — California appears to be barrelling toward a Senate contest that could easily become the craziest of the cycle: a civil war between some of America's top Democrats about what it means to be a progressive in the year 2024.

"In the absence of a competitive state Republican Party, this race is an opportunity to see a more undiluted version of the fight that national Democrats will have in the years ahead," says Dan Schnur, a former strategist for Sen. John McCain and California Gov. Pete Wilson who now teaches politics at several leading California universities. "Each likely candidate represents a different component of the party's progressive base, so they're going to offer a lot of different definitions of 'progressive' for Democratic voters."

Schiff isn’t the first Golden State Dem to set his sights on Feinstein’s seat, and he probably won’t be the last. Just days into the new year, Rep. Katie Porter of Orange County got a head start when she revealed that she would be running regardless of whether Feinstein stays or goes.

"I have tremendous respect for Sen. Feinstein and respect her wanting to take her own time," Porter told the Los Angeles Times. But even "if the senator decides to run for another term ... I will still be in this race."

Lest she be outmaneuvered, longtime Oakland Rep. Barbara Lee informed her colleagues in a closed-door Congressional Black Caucus meeting the following day that she's also planning to compete for Feinstein's seat, according to Politico.

At that point, it was only a matter of time before Schiff threw his hat in the proverbial ring, declaring Thursday that California "need[s] a fighter in the U.S. Senate who has been at the center of the struggle for our democracy.”

And at least one other marquee Democrat — Silicon Valley Rep. Ro Khanna — is considering a bid. "In the next few months, I will make a decision," Khanna told NBC News on Jan. 10.

Despite insisting that she won't make her intentions known until 2024, Feinstein is exceedingly unlikely to seek a sixth full term. The oldest sitting senator — and the fifth oldest in U.S. history — she has suffered for years from memory issues that have raised questions about her fitness to serve, and she recently passed on becoming president pro tempore of the Senate, which would have put her third in line to the presidency.

Feinstein was expected to make an announcement about her future by the spring until Porter stepped on her toes.

“All Feinstein has wanted for a long time is to make the decision on her own terms,” says Schnur. “But now Porter has kept that from happening, so Feinstein is trying to preserve as much of her dignity as possible.”

At the latest, California insiders expect the senator to bow out by next December — the final deadline to declare for the state's March 5, 2024 primary — and likely much earlier. (On Thursday, a Feinstein spokesperson clarified that "Senator Feinstein was speaking about the timing of the election, not her announcement" and that "she still intends to announce her decision in the coming months.")

Tellingly, the Democrats looking to replace Feinstein aren’t waiting around. California has a “jungle primary” system, with candidates of all parties competing against each other to win 50% of the vote in an initial round of balloting, followed by a general-election runoff between the top two finishers — again, regardless of party label — if no one manages to clear that threshold.

That means the real action will happen next March.

If Republicans field “a semi-plausible but ultimately unsuccessful candidate like they have in recent governor's races,” says Schnur, it’s conceivable that he or she could sneak into the top two before proceeding to (and then losing) the general election — particularly if Democrats divide their vote among three or more solid contenders.

Otherwise, Schnur explains, Republicans may “just completely forfeit, the way they have in the last couple of Senate campaigns,” in which case the top two Democrats would face off again in the fall.

Either way, the system will encourage each Democrat to carve out their own unique niche in the hopes of securing just enough votes to survive until Round Two — a dynamic that will almost certainly accentuate the deeper Democratic divisions they embody.

The two Southern Californians (Porter and Schiff) have the most money in the bank ($7 million and $20 million, respectively), and the biggest national profiles. (Facing serious GOP challengers in her Orange County swing district, Porter in particular has become one of the party's most prolific fundraisers, raking in a cool $25 million last cycle.) The two northern Californians (Lee and Khanna) are less loaded, but perhaps more beloved in certain corners of the left.

An early statewide poll commissioned by the Porter campaign showed Porter leading the potential primary field with 30%, ahead of Schiff (29%) Lee (9%) and Khanna (6%). In a top-two runoff, Porter led Schiff by 11 percentage points.

Yet any one of them has the potential to win.

To do so, each Democrat will emphasize his or her distinctive brand of progressivism — brands that neatly map the various directions the party as a whole could go in coming years.

As a former leader of the Congressional Black Caucus with deep roots in the East Bay's activist scene, Lee, 76, represents two of the most enduring sources of Democratic strength: the Black community and urban liberals. (In 2001, Lee cemented her progressive bona fides when she became the lone member of Congress to vote against authorizing the war in Afghanistan.) As a result, Lee's candidacy will test, in part, whether the factor that puts "a candidate over the top is appeal to the base, and that's people of color, particularly women of color," as Aimee Allison, president and founder of She the People, recently told the Sacramento Bee.

It will also test how eager California Democrats are for generational change; according to a San Francisco Chronicle report, Lee's team is already trying to address age concerns by "pitching her to donors as a transitional candidate who'd serve [only] one term."

Schiff's brand is also tried and true — a throwback of sorts to the Trump Era, when he managed the former president's first impeachment trial and leveraged his role as chair of the House Intelligence Committee to become the face of anti-Trump activity on the left. "A dangerous demagogue tried to undermine our democracy," Schiff, 62, said in his announcement video, amid a montage of MAGA figures (Trump included) singling him out for criticism. "I wasn't about to let him." The test here is whether making enemies with Trump is still the best way to make friends with progressives.

Meanwhile, the two younger contenders, Porter (49) and Khanna (46), represent less conventional versions of progressivism. In part that’s because of their unique identities; Porter is the single working mother of young children; Khanna is the son of Punjabi Hindu immigrants. But it’s also because of how they aspire to advance the agendas of their progressive mentors: Massachusetts Sen. Elizabeth Warren (in Porter’s case) and Vermont Sen. Bernie Sanders (in Khanna’s).

A former student of Warren's at Harvard Law School, Porter has displayed a Warren-like knack for exposing corporate chicanery and demystifying special-interest complexities, often utilizing her signature "whiteboard" to relentlessly interrogate Congressional witnesses. "She stands up to Wall Street and Big Pharma," Warren said in an endorsement video released immediately after Porter's announcement. "She holds fossil fuel companies accountable. And she fights for all our rights. We need her — and her whiteboard — in the United States Senate."

If Porter aims to be the next anti-corporate crusader, then Khanna is angling to be the next big-picture, Sanderesque populist. As the congressman from Silicon Valley, he often calls for a "new New Deal" or a "new economic patriotism" that he claims would heal partisan divides and shield workers from the worst effects of globalization by reviving domestic manufacturing and bringing tech jobs to decimated rural areas.

“Porter's progressive argument is based on ideology. Lee's is based on demographics. Schiff’s is based on Trump,” says Schnur. “So if you call yourself a California progressive, do you vote on ideology, do you vote on demographics or or do you vote on Trump?”

The contours of the California Senate contest are still in flux; Khanna, for one, could skip the race as he plots a path to even higher office. (According to Politico, "top figures from Bernie Sanders' presidential campaign are privately encouraging [him] to run for president in 2024 if Joe Biden doesn't seek a second term.")

But the sniping, at least, has already begun, with both Khanna and Schiff going out of their way to tweak Porter for launching her candidacy while historic storms were inundating the state.

In other words, it’s clear even now that California is going to be a Democratic slugfest in 2024 — and a very revealing one at that.