A mild-mannered former prosecutor, Schiff built a profile as a moderate Democrat focused on foreign policy and national security. The Trump era, however, thrust him into the spotlight, as he led the first impeachment of the then-president and served on the congressional panel investigating the Jan. 6 Capitol attack that culminated in referring Trump to the Justice Department for criminal investigation.

“The Senate is where many of these fights over the future of our democracy take place,” Schiff said in an interview prior to his campaign launch. “Some of Donald Trump’s biggest enablers are in the Senate. And I think that is where I can most effectively champion our democratic institutions.”

His campaign injects new fundraising and political heft to the race for the Senate seat currently occupied by Sen. Dianne Feinstein, the San Francisco Democrat who has held that office for 30 years.

Democratic Rep. Katie Porter, a rising star in the party who has notched close victories in competitive Orange County, was the first major candidate to declare her Senate candidacy this month. Oakland Rep. Barbara Lee, a progressive Democrat, told colleagues she also will launch a bid, although she has not yet done so publicly. Democratic Rep. Ro Khanna of Fremont also has signaled interest in running.

Though the race for Feinstein’s seat has begun in earnest, the 89-year-old has not disclosed whether she intends to seek reelection next year. Given some questions about her capacity to continue in that role, many observers expect she will not run for another six-year term.

“I have just tremendous respect for her and — more than respect — admiration and affection,” Schiff said, adding that he would not have jumped into the race without informing her first. He said they spoke the day before his announcement.

“I think she will make her own decision about an announcement when she feels ready to do so,” he said. “She’s earned that right, and I certainly respect her to do that whenever she determines the time is right.”

Feinstein had previously told The Times she would disclose her plans “probably by spring.”

With Republicans having trouble mustering competitive candidates to run for statewide office, the fiercest battle is expected to be among the Democratic contenders, who broadly align on ideology.

“Since they do mostly fall in line in terms of policy, it’ll be a race more about personality and about brand,” said Kimberly Nalder, a Sacramento State University political scientist.

She pointed to Lee’s reputation as the lone vote in Congress against the Afghanistan war in 2001, which “makes her a hero to the left,” Nalder said, but also reflecting the position that a majority in the country now holds.

Porter, of Irvine, meanwhile, has emerged as an anti-corruption advocate with a populist streak and a whiteboard as her signature prop.

Schiff’s lawyerly demeanor is now best associated with the impeachment and Jan. 6 hearings.

“We saw in 2022 that democracy itself was a big issue for a lot of voters,” Nalder said. “He certainly was a very visible defender of democracy in those hearings, for those who paid attention.”

Schiff shared that assessment, telling The Times that his role “at the center of these fights to preserve democracy” will differentiate himself from his competitors. Those fights, he said, were “interlinked” with voters’ concerns about the economy.

“The fact that the economy hasn’t been working for millions of Americans who have seen their quality of life decline … led people to be receptive to a demagogue who comes with promises that he alone can fix it,” he said, citing climate change as another main campaign focus.

His kickoff campaign video flaunts anti-endorsements from prominent right-wingers such as Trump — shown referring to the congressman derisively as “Little Pencil Neck” — and Fox News personality Tucker Carlson, who called him “unfit to hold office.”

Schiff’s record as chief Trump antagonist landed him on the bestseller lists with a memoir, “Midnight in Washington.” He also parlayed the notoriety into a campaign cash juggernaut. He had more than $20 million on hand as of late November, catapulting him to the finance lead among his rivals in the Senate race. His campaign will not accept donations from corporate political action committees, a spokesperson said.

Porter has also shown fundraising prowess while eschewing corporate PAC contributions, pulling in more than $25 million for her last congressional campaign. But she spent heavily last cycle to fend off her Republican challenger, leaving her with $7.7 million in the bank after the election. Lee, who has faced little competition in her deep-blue Oakland district, spent more than $2 million in her last campaign and ended less than $55,000 in the bank.

For Schiff, 62, the statewide bid will mark the first time in 20 years he has faced a competitive race.

Born in Massachusetts and raised in Arizona and the Bay Area, Schiff moved to Los Angeles after law school to clerk for a federal judge. As a deputy in the U.S. attorney’s office, he successfully prosecuted Richard Miller, the first FBI agent to be indicted for espionage.

He then attempted to make the jump to elected office. Though a 1994 state Assembly run was unsuccessful, he won a GOP-held state Senate seat two years later.

Though now a Democratic stronghold, the intersection of the San Fernando and San Gabriel valleys — encompassing Burbank, Glendale and Pasadena — was friendlier territory for Republicans when Schiff ran for Congress in 2000. He squared off against GOP Rep. James Rogan, who had bested Schiff six years earlier for an Assembly seat and, while in Congress, emerged as a central figure in the Republican impeachment of President Clinton.

Schiff emerged victorious in the hotly fought campaign, which shattered spending records for House races. Since then, he has routinely won reelection by 30- to 50-point margins.

In 2001, the first-term congressman was preparing to go to work when the first plane struck the World Trade Center on Sept. 11; the terrorist attacks ended up shaping his course in Congress, pushing him to focus more on national security than other policy areas that had interested him, such as environmental issues or criminal justice reform.

“I thought that there aren’t that many people in the caucus, compared to other areas, who are focused on this,” he told The Times on the 20th anniversary of 9/11. “Maybe this is where I can add value.”

Schiff voted for the Iraq war authorization in 2002, as well as for the Patriot Act. Years later, he told The Times that an “overriding impact [of 9/11 and the ensuing years] is a recognition of the limitations of military power.” As he rose in prominence in the House Intelligence Committee, he became a leading congressional voice on seeking congressional authorization for military force against the Islamic State and in favor of the Iran nuclear deal negotiated during the Obama administration.

As the top Democrat on the Intelligence Committee, he was a central figure in several investigations into Trump. He vocally drew attention to Russian interference in the 2016 presidential election, which was investigated by special counsel Robert S. Mueller III. His prominence earned him derisive nicknames from Trump and the ire of Republicans, who accused him of making exaggerated and politicized claims that Trump’s campaign colluded with the Russian government.

He became even more of a lightning rod as leader of the first impeachment inquiry into Trump. Schiff presided over hearings that examined whether Trump tried to pressure the president of Ukraine to open an investigation into his rival Joe Biden in exchange for military aid. Trump was impeached by the Democratic-led House but was acquitted in the Senate.

A top ally of then-Speaker Nancy Pelosi (D-San Francisco), Schiff reportedly considered following in her footsteps in a House Democratic leadership role. He ultimately decided to focus on a bid for the Senate instead.

His congressional workload may lighten considerably this term. House Speaker Kevin McCarthy (R-Bakersfield) removed him this week from the Intelligence Committee, alleging that Schiff lied about whether he knew the whistleblower whose complaint led to Trump’s first impeachment. (A Washington Post fact-check disputed McCarthy’s accusation.)

McCarthy, explaining his actions in a letter, said the Intelligence Committee under Schiff’s chairmanship “severely undermined its primary national security and oversight missions — ultimately leaving our nation less safe.”

The move, along with removing Rep. Eric Swalwell (D-Dublin) from the committee, appeared to be in retaliation for Democrats leading a bipartisan effort in stripping assignments from Reps. Marjorie Taylor Greene (R-Ga.) and Paul Gosar (R-Ariz.) for making incendiary comments including threats against their colleagues.

Schiff denounced the move as “destructive of the institution” of the intelligence panel. But he appeared to relish the chance to needle the fellow Californian, charging that McCarthy was more inclined to help the far-right flank of the party than his own state.

“There will certainly be a form of cosmic justice when I become Kevin McCarthy’s home state senator,” Schiff said.