WASHINGTON — U.S. Sen. Dianne Feinstein of California, a centrist Democrat and champion of liberal causes who was elected to the Senate in 1992 and broke gender barriers throughout her long career in local and national politics, has died. She was 90.

Feinstein died on Thursday night at her home in Washington, D.C., her office said on Friday. Opening the Senate floor, Senate Majority Leader Chuck Schumer announced that “earlier this morning, we lost a giant in the Senate.”

“Dianne Feinstein was one of the most amazing people who ever graced the Senate, who ever graced the country,” Schumer said, his voice cracking. “As the nation mourns this tremendous loss, we know how many lives she impacted and how many glass ceilings she shattered along the way.”

President Joe Biden, who served with Feinstein for years in the Senate, called her “a pioneering American,” a “true trailblazer” and a “cherished friend.”

California Gov. Gavin Newsom will appoint a temporary replacement, and there is sure to be a spirited battle to succeed her.

Feinstein, the oldest sitting U.S. senator, was a passionate advocate for liberal priorities important to her state — including environmental protection, reproductive rights and gun control — but was also known as a pragmatic lawmaker who reached out to Republicans and sought middle ground.

Her death came after a bout of shingles sidelined her for more than two months earlier this year — an absence that drew frustration from her most liberal critics and launched an unsuccessful attempt by Democrats to temporarily replace her on the Senate Judiciary Committee. When she returned to the Senate in May, she was frail and using a wheelchair, voting only occasionally.

On Friday morning, her Senate desk was draped in black and topped with a vase of white roses. Senators gave tearful tributes as members of the California House delegation stood in the back of the chamber and former House Speaker Nancy Pelosi sat in the gallery with Feinstein's daughter, Katherine.

Senate Republican Leader Mitch McConnell was one of several Republicans who gave tributes to the Democratic icon, calling her his friend. “Dianne was a trailblazer, and her beloved home state of California and our entire nation are better for her dogged advocacy and diligent service,” McConnell said.

Biden said in a statement, “Dianne made her mark on everything from national security to the environment to protecting civil liberties. “Our country will benefit from her legacy for generations.”

Former President Barack Obama also saluted her as “a trailblazer,” and former President Bill Clinton called her a champion “of civil rights and civil liberties, environmental protection and strong national security.”

She was elected to the San Francisco Board of Supervisors in 1969 and became its first female board president in 1978, the year Mayor George Moscone was gunned down alongside Supervisor Harvey Milk at City Hall by Dan White, a disgruntled former supervisor. Feinstein found Milk's body.

After Moscone's death, Feinstein became San Francisco's first female mayor. In the Senate, she was one of California's first two female senators, the first woman to head the Senate Intelligence Committee and the first woman to serve as the Judiciary Committee's top Democrat.

Although Feinstein was not always embraced by the feminist movement, her experiences colored her outlook through her five decades in politics.

“I recognize that women have had to fight for everything they have gotten, every right,” she told The Associated Press in 2005, as the Judiciary Committee prepared to hold hearings on President George W. Bush's nomination of John Roberts to replace Sandra Day O'Connor on the Supreme Court.

“So I must tell you, I try to look out for women's rights. I also try to solve problems as I perceive them, with legislation, and reaching out where I can, and working across the aisle,” she said.

Feinstein's bipartisan efforts helped her notch legislative wins throughout her career. But it also proved to be a liability in her later years in Congress, as her state became more liberal and as the Senate and the electorate became increasingly polarized.

A fierce debater who did not suffer fools, the California senator was long known for her verbal zingers and sharp comebacks when challenged on the issues about which she was most fervent. But she lost that edge in her later years in the Senate, as her health visibly declined and she sometimes became confused when answering questions or speaking publicly. In February 2023, she said she would not run for a sixth term the next year. And within weeks of that announcement, she was absent for the Senate for more than two months as she recovered from a bout of shingles.

Amid the concerns about her health, Feinstein stepped down as the top Democrat on the Judiciary panel after the 2020 elections, just as her party was about to take the majority. In 2023, she said she would not serve as the Senate president pro tempore, or the most senior member of the majority party, even though she was in line to do so. The president pro tempore opens the Senate every day and holds other ceremonial duties.

One of Feinstein's most significant legislative accomplishments was early in her career, when the Senate approved her amendment to ban manufacturing and sales of certain types of assault weapons as part of a crime bill that President Bill Clinton signed into law in 1994. Though the assault weapons ban expired 10 years later and was never renewed or replaced, it was a poignant win after her career had been significantly shaped by gun violence.

Feinstein remembered finding Milk's body, her finger slipping into a bullet hole as she felt for a pulse. It was a story she would retell often in the years ahead as she pushed for stricter gun control measures.

She had little patience for Republicans and others who opposed her on that issue, though she was often challenged. In 1993, during debate on the assault weapons ban, Sen. Larry Craig, R-Idaho, accused her of having an insufficient knowledge of guns and the gun control issue.

Feinstein spoke fiercely of the violence she'd lived through in San Francisco and retorted: ''Senator, I know something about what firearms can do.”

Two decades later, after 20 children and six educators were killed in a horrific school shooting in Newtown, Connecticut, first-term Republican Sen. Ted Cruz of Texas similarly challenged Feinstein during debate on legislation that would have permanently banned the weapons.

“I'm not a sixth grader,” Feinstein snapped back at the much younger Cruz — a moment that later went viral. She added: “It's fine you want to lecture me on the Constitution. I appreciate it. Just know I've been here a long time.”

Feinstein became mayor of San Francisco after the 1978 slayings of Moscone and Milk, leading the city during one of the most turbulent periods in its history. Even her critics credited Feinstein with a calming influence, and she won reelection on her own to two four-year terms.

With her success and growing recognition statewide came visibility on the national political stage.

In 1984, Feinstein was viewed as a vice presidential possibility for Walter Mondale but faced questions about the business dealings of her husband, Richard Blum. In 1990, she used news footage of her announcement of the assassinations of Moscone and Milk in a television ad that helped her win the Democratic nomination for California governor, making her the first female major-party gubernatorial nominee in the state's history.

Although she narrowly lost the general election to Republican Pete Wilson, the stage was set for her election to the Senate two years later to fill the Senate seat Wilson had vacated to run for governor.

Feinstein campaigned jointly with Barbara Boxer, who was running for the state's other U.S. Senate seat, and both won, benefiting from positive news coverage and excitement over their historic race. California had never had a female U.S. senator, and female candidates and voters had been galvanized by the Supreme Court hearings in which the all-male Senate Judiciary Committee questioned Anita Hill about her sexual harassment allegations against nominee Clarence Thomas.

Feinstein was appointed to the Judiciary panel and eventually the Senate Intelligence Committee, becoming the chairperson in 2009. She was the first woman to lead the intelligence panel, a high-profile perch that gave her a central oversight role over U.S. intelligence controversies, setbacks and triumphs, from the killing of Osama bin Laden to leaks about National Security Agency surveillance.

Under Feinstein's leadership, the intelligence committee conducted a wide-ranging, five-year investigation into CIA interrogation techniques during President George W. Bush's administration, including waterboarding of terrorism suspects at secret overseas prisons. The resulting 6,300-page “torture report” concluded among other things that waterboarding and other “enhanced interrogation techniques” did not provide key evidence in the hunt for bin Laden. A 525-page executive summary was released in late 2014, but the rest of the report has remained classified.

The Senate investigation was full of intrigue at the time, including documents that mysteriously disappeared and accusations traded between the Senate and the CIA that the other was stealing information. The drama was captured in a 2019 movie about the investigation called “The Report,” and actor Annette Bening was nominated for a Golden Globe for her portrayal of Feinstein.

In the years since, Feinstein has continued to push aggressively for eventual declassification of the report.

“It's my very strong belief that one day this report should be declassified,” Feinstein said. “This must be a lesson learned: that torture doesn't work.”

Feinstein sometimes frustrated liberals by adopting moderate or hawkish positions that put her at odds with the left wing of the Democratic Party, as well as with the more liberal Boxer, who retired from the Senate in 2017. Feinstein defended the Obama administration's expansive collection of Americans' phone and email records as necessary for protecting the country, for example, even as other Democratic senators voiced protests. “It's called protecting America,” Feinstein said then.

That tension escalated during Donald Trump's presidency, when many Democrats had little appetite for compromise. Feinstein became the top Democrat on the Judiciary panel in 2016 and led her party's messaging through three Supreme Court nominations — a role that angered liberal advocacy groups that wanted to see a more aggressive partisan in charge.

Feinstein closed out confirmation hearings for Justice Amy Coney Barrett with an embrace of Senate Judiciary Committee Chair Lindsey Graham, R-S.C., and a public thanks to him for a job well done. “This has been one of the best set of hearings that I've participated in,” Feinstein said at the end of the hearing.

Liberal advocacy groups that had fiercely opposed Barrett’s nomination to replace the late liberal icon Justice Ruth Bader Ginsburg were furious and called for her to step down from the committee leadership.

A month later, Feinstein announced she would remain on the committee but step down as the top Democrat. The senator, then 87 years old, did not say why. In a statement, she said she would “continue to do my utmost to bring about positive change in the coming years.”

Feinstein was born on June 22, 1933. Her father, Leon Goldman, was a prominent surgeon and medical school professor in San Francisco, but her mother was an abusive woman with a violent temper that was often directed at Feinstein and her two younger sisters.

Feinstein graduated from Stanford University in 1955, with a bachelor's degree in history. She married young and was a divorced single mother of her daughter, Katherine, in 1960, at a time when such a status was still unusual.

In 1961, Feinstein was appointed by then-Gov. Pat Brown to the women's parole board, on which she served before running for the San Francisco Board of Supervisors. Typical of the era, much of the early coverage of her entrance into public life focused on her appearance rather than her experience and education.

Feinstein’s second husband, Bert Feinstein, was 19 years older than she, but she described the marriage as “a 10" and kept his name even after his death from cancer in 1978. In 1980, she married investment banker Richard Blum, and thanks to his wealth, she was one of the richest members of the Senate. He died in February 2022.

In addition to her daughter, Feinstein has a granddaughter, Eileen, and three stepchildren.