Dianne Feinstein, the grande dame of California Democrats who became the mayor of San Francisco after a horrific double assassination at City Hall in 1978 and then gained national stature as an influential voice in the United States Senate for more than 30 years, died on Thursday night at her home in Washington. She was 90 and the Senate’s oldest member.
Her death was confirmed by family members, who did not cite a cause. Ms. Feinstein had returned to the Senate in May, appearing frail and using a wheelchair, after a two-month absence during which she was treated for shingles that had spread to her neck and face and that had led to encephalitis, a rare complication that causes swelling of the brain, among other symptoms.
Her death comes more than seven months after she announced that she intended to retire at the end of her term in January 2025. The news concluded a protracted guessing game as to whether she would seek another term on Capitol Hill at her advanced age, and it set off a scramble among California Democrats eager to succeed her.
Ms. Feinstein’s political life first gained traction during a volatile period in San Francisco and played out in tense Senate years, when an impeached President Bill Clinton was acquitted and the nation went to war in Afghanistan and Iraq. Throughout, she was an eloquent champion of civil rights and gun control who defended and also denounced national security measures in the age of terrorism.