The California Democratic Party handed Sen. Dianne Feinstein a striking rejection on Saturday, as party leaders endorsed her progressive challenger Kevin de León.

The endorsement, voted on by the state party’s executive board at a meeting in Oakland, gives De León a big morale boost as he faces an uphill race against the 26-year incumbent.

De León, a state senator from Los Angeles and the former leader of the state Senate, won 65 percent of the 333 delegates, according to the party. Feinstein netted 7 percent after urging her supporters to choose no endorsement “in the name of party unity.”

De León appealed to the party faithful by blasting President Donald Trump and embracing policies like single-payer health care and abolishing the Immigration and Customs Enforcement agency, while tapping into discontentment with Feinstein among the party’s left flank.

“Today’s vote is a clear-eyed rejection of politics as usual in Washington, D.C.,” De León said in a statement. “The nation’s most accomplished Democratic Party is leading the call for a new generation of leadership who will fight to advance a bold agenda.”

Pro-De León activists erupted in cheers at Oakland’s Marriott City Center hotel as rumors leaked out about his victory Saturday evening.

“It shows that California Democrats expect strong progressive stances from our legislators,” said David Atkins, a delegate from Santa Barbara, between hugs with his fellow De León supporters. “We’re part of a movement in this party.”

Still, Feinstein remains a strong favorite for November — she won 44 percent in the June top-two primary to De León’s 12 percent, and has a sizable fundraising advantage.

“The reality here is that he got beat by over 30 points,” said Bill Carrick, Feinstein’s longtime strategist. “We should move on beyond the primary fights and try to win elections against Republicans.”

The endorsement means De León will be able to raise funds in coordination with the party and be featured in Democratic mailers. It will also likely net him a wave of national attention and donations.

Feinstein, who at 82 is the oldest current U.S. senator, had been calling in political favors in recent weeks to argue for a no endorsement vote. Her campaign sent a letter to executive board members from a half dozen of the party’s House candidates in key California seats asking leaders to abstain from supporting Feinstein or De León.

Neither Feinstein nor De León won the endorsement in the primary campaign at the Democratic convention in February, where De León got the support of 54 percent of the delegates — just under the 60 percent threshold necessary to win the endorsement.

De León’s endorsement coup echoes other wins for progressives in recent weeks, including New York candidate Alexandria Ocasio-Cortez, who electrified liberals by defeating the number-four Democrat in the House of Representatives last month.

The contrast between the two candidates was on show as they rushed between caucus meetings on Saturday.

“Seniority matters,” Feinstein told her supporters over a breakfast of bacon and eggs, reminding them that she was the top Democrat on the Senate committee that will hold hearings on President Trump’s Supreme Court nominee, Brett Kavanaugh.

“This man will be the deciding vote on those things we hold most dear,” including the Roe v. Wade decision, she said. She said she and her committee would review “over one million pieces of paper” of Kavanaugh’s past opinions and other documents about his record, in an attempt to make a case against his nomination.

But De León argued that the hearings Feinstein is preparing for shouldn’t even take place.

“We need to shut the Senate down and never allow this individual to come to the Senate floor,” he declared to cheers at another caucus meeting later that morning. “What’s at stake is a generation of power, decisions that will affect each and every one of us.”

De León’s campaign argued that his connections with party activists will help him in the endorsement face-off, while Feinstein has invested less time in recent years engaging party activists.

“These are relationships he’s been building for 10 years or longer,” said Jonathan Underland, a De León spokesman, said this week. “The idea that he is trying to divide the party is just laughable.”

The Democrats walking the halls in Oakland are fired up over Trump and optimistic about their chances to take back the House in November. The most popular figure here has been Rep. Maxine Waters, who’s been attacked by the president after encouraging protests against him and his staffers. She won huge cheers when she declared Saturday that Trump was “embarrassing us every day.”

The Senate race remains the biggest sticking point, splitting Democrats over questions of liberal bona fides and generational leadership.

“You don’t need to replace someone who’s doing their job,” said labor rights organizer Dolores Huerta, who sat next to Feinstein at her breakfast. “Why do you want to go in there and divide the party?”

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But De León’s backers said they were ready for a more progressive vision as the Golden State faces down the Trump administration. “I appreciate everything Dianne’s done for the state, but it’s time for some new blood and new values,” said David Weiner, a delegate from Palm Springs.

Feinstein has clashed with the state party faithful before, losing the Democratic endorsement in campaigns for governor and U.S. Senate in 1990 and 1992. In 1990, she dramatically declared her support for the death penalty at the state convention, over loud boos from the hall — and then her campaign cut an ad featuring the footage to show her independence.

In a sign of how Feinstein has moved to the left as she faces De León’s, she said earlier this year that she now opposes capital punishment.

“The folks who show up at Democratic executive board meetings have never been Dianne Feinstein’s base,” said Darry Sragow, a strategist who ran Feinstein’s 1990 campaign and isn’t working for either camp this year. “[De León] gaining the endorsement is not going to get him the votes he needs to win — but it’ll be an opportunity to put a point on the board when he has very few of those.”