Dianne Feinstein, whose three decades in the Senate made her the longest-serving female US senator in history, has died, according to a source familiar. She was 90. (Alex Wong/Getty Images)

Washington (CNN) — Dianne Feinstein, whose three decades in the Senate made her the longest-serving female US senator in history, has died following months of declining health. She was 90.

Feinstein, a Democrat, died Thursday night at her home in Washington, her office said in a statement.

Her death hands California Democratic Gov. Gavin Newsom the power to appoint a lawmaker to serve out the rest of Feinstein’s term, keeping the Democratic majority in the chamber through early January 2025. Newsom has publicly pledged to appoint a Black woman if Feinstein were to vacate her office and told NBC’s “Meet the Press” earlier this month that he would make an “interim appointment” who wouldn’t be any of the candidates who are seeking the seat in next year’s election.

Feinstein’s death also comes as federal funding is set to expire and Congress at an impasse as to how to avoid a government shutdown, though Senate Democrats still retain a majority without her.

Feinstein, a former mayor of San Francisco, was a leading figure in California politics for decades and became a national face of the Democratic Party following her first election to the US Senate in 1992. She broke a series of glass ceilings throughout her political career and her influence was felt strongly in some of Capitol Hill’s most consequential works in recent history, including the since-lapsed federal assault weapons ban in 1994 and the 2014 CIA torture report. She also was a longtime force on the Senate Intelligence and Judiciary committees.

In her later years, Feinstein’s health was the subject of increasing speculation, and the California Democrat was prominent among aging lawmakers whose decisions to remain in office drew scrutiny, especially in an age of narrow party margins in Congress.

A hospitalization for shingles in February led to an extended absence from the Senate – stirring complaints from Democrats, as Feinstein’s time away slowed the confirmation of Democratic-appointed judicial nominees – and when she returned to Capitol Hill three months later, it was revealed that she had suffered multiple complications during her recovery, including Ramsay Hunt syndrome and encephalitis. A fall in August briefly sent her to the hospital.

Feinstein, who was the Senate’s oldest member at the time of her death, also faced questions about her mental acuity and ability to lead. She dismissed the concerns, saying, “The real question is whether I’m still an effective representative for 40 million Californians, and the record shows that I am.”

But heavy speculation that Feinstein would retire instead of seek reelection in 2024 led several Democrats to announce their candidacies for her seat – even before she announced her plans. In February, she confirmed that she would not run for reelection, telling CNN, “The time has come.”

Feinstein was fondly remembered by her colleagues on Friday.

Rep. Nancy Pelosi hailed her fellow Californian as a “champion for the Golden State” and Democratic Sen. Dick Durbin of Illinois remembered her as “one of the great ones.” Republican House Speaker Kevin McCarthy, also of California, began his remarks to reporters Friday morning by honoring Feinstein as someone who “blazed a trail for women.”

In emotional remarks on the Senate floor, Majority Leader Chuck Schumer asked for a moment of silence. Per Senate tradition, Feinstein’s desk was draped with a black cloth with a vase of white flowers atop it.

“Dianne Feinstein is not like the others. She’s in a class of her own,” Schumer said, later adding, “America is a better place because of Sen. Dianne Feinstein.”

And President Joe Biden, himself a longtime colleague of Feinstein’s for more than 15 years, called her a “cherished friend.”

San Francisco native and leader

Feinstein was born in San Francisco in 1933 and graduated from Stanford University in 1955. After serving as a San Francisco County supervisor, Feinstein became the city’s mayor in 1978 in the wake of the assassination of Mayor George Moscone and Supervisor Harvey Milk, the first openly gay politician from California to be elected to office.

Feinstein rarely talked about the day when Moscone and Milk were shot but she opened up about the tragic events in a 2017 interview with CNN’s Dana Bash.

Feinstein was on the San Francisco Board of Supervisors then, and assassin Dan White had been a friend and colleague of hers.

“The door to the office opened, and he came in, and I said, ‘Dan?’ ”

“I heard the doors slam, I heard the shots, I smelled the cordite,” Feinstein recalled.

It was Feinstein who announced the double assassination to the public. She was later sworn in as the first female mayor of San Francisco.

Her political career was marked by a series of historic firsts.

By that time she became mayor in 1978, she had already broken one glass ceiling, becoming the first female chair of the San Francisco Board of Supervisors.

California’s first woman sent to the US Senate racked up many other firsts in Washington. Among those: She was the first woman to sit on the Senate Judiciary Committee, the first female chairwoman of the Senate Rules and Administration Committee, and the first female chair of the Senate Intelligence Committee.

Feinstein also served on the powerful Senate Appropriations Committee and held the title of ranking member of the Senate Judiciary Committee from 2017 to 2021. In November 2022, she was poised to become president pro tempore of the Senate – third in line to the presidency – but declined to pursue the position, citing her husband’s recent death.

Feinstein reflected on her experience as a woman in politics in her 2017 interview with Bash, saying, “Look, being a woman in our society even today is difficult,” and noting, “I know it in the political area.” She would later note in a statement the week she became the longest-serving woman in US history, “We went from two women senators when I ran for office in 1992 to 24 today – and I know that number will keep climbing.”

“It has been a great pleasure to watch more and more women walk the halls of the Senate,” Feinstein said in November 2022.

Led efforts on gun control and torture program investigations

Though she was a proud native of one of the most famously liberal cities in the country, Feinstein earned a reputation over the years in the Senate as someone eager to work across the aisle with Republicans, and at times sparked pushback and criticism from progressives.

“I truly believe that there is a center in the political spectrum that is the best place to run something when you have a very diverse community. America is diverse; we are not all one people. We are many different colors, religions, backgrounds, education levels, all of it,” she told CNN in 2017.

biography from Feinstein’s Senate office states that her notable achievements include “the enactment of the federal Assault Weapons Ban in 1994, a law that prohibited the sale, manufacture and import of military-style assault weapons” (the ban has since lapsed), and the influential 2014 torture report, a comprehensive “six-year review of the CIA’s detention and interrogation program,” which brought to light for the first time many details from the George W. Bush-era program.

Feinstein’s high-profile Senate career made its mark on pop culture when she was portrayed by actress Annette Bening in the 2019 film “The Report,” which tackled the subject of the CIA’s use of torture after the Sept. 11 attacks and the effort to make those practices public.

In November 2020, Feinstein announced that she would step down from the top Democratic spot on the Senate Judiciary Committee the following year in the wake of sharp criticism from liberal activists over her handling of the hearings for then-President Donald Trump’s Supreme Court nominee Amy Coney Barrett.

While Democratic senators could not block Barrett’s nomination in the Republican-led Senate on their own, liberal activists were angry when Feinstein undermined Democrats’ relentless attempt to portray the process as illegitimate when she praised then-Judiciary Chairman and South Carolina Republican Lindsey Graham’s leadership of it.

Feinstein said at the time that she would continue to serve as a senior Democrat on the Judiciary, Intelligence, Appropriations, and Rules and Administration panels, working on priorities like gun safety, criminal justice and immigration.