California’s 25th district is not lacking for drama.

Made up of suburbs that wrap around the northern edge of Los Angeles, this longtime Republican district is the one that Katie Hill flipped in a high-profile 2018 race. Last year, the 32-year-old ascendant Democrat resigned, after a conservative news site published nude photos of her and amid a congressional ethics probe. Among the more than 10 candidates vying to take her seat are the Republican she bested; a former Navy strike fighter pilot; an establishment-backed state assemblywoman; a liberal talk show host with a history of making off-color comments and a former Trump campaign aide who pleaded guilty to lying to the FBI and served 12 days in prison.

“This is the candidate field most worthy of their own reality show,” says Thad Kousser, a political science professor at the University of California, San Diego. But that is just the local reason that the race is one to watch: With a special election vote approaching on March 3, the choices made by voters in this California district could serve as a bellwether for the broader fate of Republicans in the state, and nationwide.

The story of Republicans in California has been one of decline. They hold no statewide offices and, as of 2018, they became the third most popular party, after Democrats and “no party preference.” Last cycle was especially rough, with seven House districts all being flipped from red to blue, thanks in part to Trump’s unpopularity in the state. And Hill’s resignation presents the GOP with the chance to win one of those seats back without having to best an incumbent propelled by a sophomore surge.

Registered Democrats outnumber Republicans by a small but increasing margin in the district, an area once known for reliably conservative voters who worked in the military and aerospace industries. Even as Latino and Asian-American voters have moved in, fleeing Los Angeles’ high prices and pushing the populace to the left, red enclaves remain. And one of the leading candidates in the race, former Rep. Steve Knight, is well-known enough that the Republican has something resembling an incumbency advantage. If the GOP cannot win here under these conditions, Kousser says, it could herald “a new era of irrelevance” in the Golden State.

The 25th could also serve as an indicator of Republican chances for taking back the House this year, a feat that would require the party to pick up at least 18 seats. “This is the kind of district they need to be able to win,” says Eric Schickler, co-director of the Institute of Governmental Studies at UC Berkeley. It’s one that the party recently held. It’s purple. It’s a place where messages about hard work and family values resonate. When Hill resigned, the Cook Political Report recategorized its 2020 prediction for the district from “Likely Democrat” to the less definite “Lean.”

A Republican strategist involved in the race, who was not authorized to speak on the record, says the outcome won’t necessarily be predictive but acknowledges that the party needs to seriously compete in places like this if there is to be hope of having a GOP Majority Leader in the near future. “It’s a seat they lost, and a suburban seat. You can’t win back the House without suburban seats, right?” they say. “It doesn’t mean it has to be in California.” Republican leadership has suggested that a path back to power could, however, rely on winning back four or five seats in the state.

Assemblywoman Christy Smith, D-Santa Clarita, and former Rep. Steve Knight (R-CA).

California State Assembly/Wikimedia Commons; David McNew—Getty Images

Knight’s stiffest competition is Democrat Christy Smith, a state assemblywoman from the area who is also a known name and has been endorsed by power-brokers ranging from Gov. Gavin Newsom to Nancy Pelosi. The former L.A. police officer is also being challenged by conservative Mike Garcia, the former Navy pilot and a first generation American whose father immigrated from Mexico. While Garcia is focusing on his military background and political-newcomer status in the hopes of winning over a range of voters, Smith, whose background is in education, is focusing on healthcare and public safety issues like wildfires.

Also angling for the rare open seat in the L.A. area is Cenk Uygur — the progressive personality behind the online news network The Young Turks, whom Bernie Sanders briefly endorsed — and George Papadopoulos, the former Trump aide, who has been promoting a book and podcast. Neither lives in the district.

The attention focused on the race, says UC San Diego’s Kousser, appears to have brought out both strong candidates and “candidates who see this as an opportunity to get their message or their names out.”

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The frontrunners’ campaigns display some examples of what moderation looks like in California politics these days. Smith isn’t demanding Medicare for all (though Uygur is). Garcia is “generally supportive” of his party’s leader, with the exception of items like Trump’s cap on state and local tax deductions, a detail of his tax plan that particularly hurt Californians.

Knight, meanwhile, is putting his public service record front-and-center and has criticized Garcia for not being more supportive of the President, despite the fact that the district went for Clinton in 2016 by a margin of nearly seven points.

“Because Donald Trump was such a drag on the ticket of the Republican party in 2018, it was just crushed in unexpected places, including this district,” says Kousser. “In 2020, Donald Trump’s name will be on the ballot, and that’s going to bring out a lot of his opponents in a state like California.”

Dave Jacobson, a Democratic strategist working with Smith, is comfortable predicting that the seven districts Democrats flipped last cycle will remain blue and notes that the party is going after even redder districts in California this year. “The President’s brand is so toxic,” Jacobson says, “that it opens up real vulnerabilities to every Republican.”

There are some bureaucratic details that could muddle the race’s crystal-ball potential. Newsom set the special election to serve the remainder of Hill’s term for March 3, the same day of the state’s presidential primary and the primary for the regular 2020 House election. So candidates like Knight and Smith will be running in two races on the same ballot: one to serve out the remainder of Hill’s term and one to serve the next. If no candidate wins a majority in the special election vote, there will be a runoff in May.

If Democrats do continue their march toward dominance in this district and others, Schickler points out that it could have costs for liberal residents of the state as well as the GOP. States with ever-bluer delegations — like California, New York and much of New England — hold a lot of sway when there’s a Democratic government in Washington, D.C. But when Republicans rule, he says, “they can adopt policies without a whole lot of concern about how it imposes costs on voters in some of these states.” Just ask residents who were shocked by their tax returns after Trump’s new law went into effect.

“When California was more balanced, then whoever was in power, California would be an important a player,” Schickler says. “Now when Republicans are in power, it’s kind of marginal.”

Write to Katy Steinmetz at katy.steinmetz@time.com.