ASMA KHALID, HOST:
The nation's oldest sitting senator will not run for reelection next year. California's Dianne Feinstein is retiring. From member station KQED in San Francisco, Marisa Lagos reports.
MARISA LAGOS, BYLINE: Dianne Feinstein first made national headlines in 1978 when she became San Francisco mayor following the assassinations of Mayor George Moscone and County Supervisor Harvey Milk. Then in 1992, she ran for U.S. Senate in what became known as the Year of the Woman. Here she is at the Democratic National Convention that summer.
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DIANNE FEINSTEIN: We Californians have a simple message. The status quo must go.
LAGOS: She was a fresh face, one of a record four women elected to the Senate that year, bringing the grand total to six. And she made history in that election alongside Barbara Boxer. It was the first time two women had ever represented a single state in the U.S. Senate. Here's retired Senator Boxer.
BARBARA BOXER: The fact that two women could get elected together, two Jewish women from the Bay Area - it was stunning. No one anticipated it at all.
LAGOS: Feinstein became a senator at 59. Now, at 89, she's squarely part of the establishment, the status quo. For much of her time in the Senate, Feinstein was a leader. She helped pass the now-expired assault weapons ban in 1994, and she went to battle with two presidential administrations, including Obama's, to fight for the release of information about the CIA's use of torture.
THAD KOUSSER: We were such a different country, such a different state.
LAGOS: Thad Kousser is a political science professor at the University of California, San Diego.
KOUSSER: California was a purple state. Certainly, this retirement feels like an epochal change in California politics.
LAGOS: Over Feinstein's tenure, California has turned solidly blue, and national party politics have become increasingly hostile, while Feinstein has remained a centrist dedicated to reaching across the aisle. That's led to criticism she's out of touch with the Democratic base. There are also questions about whether she's declined mentally. And even before Feinstein's announcement, two high-profile Southern California Congress members - Adam Schiff and Katie Porter - announced they would run for her seat. Kousser says they're both to the left of Feinstein.
KOUSSER: I think we're going to spend $100 million deciding which progressive Democrat is going to represent the state of California.
LAGOS: But for the next two years, Feinstein has promised to continue the battle she's been fighting for the last three decades.
For NPR News, I'm Marisa Lagos in San Francisco. Transcript provided by NPR, Copyright NPR.