Dianne Feinstein, elected to the Senate in 1992, is the longest-serving woman in the history of the Senate. (Credit: Senate Democrats, Flickr)

Sen. Dianne Feinstein (D-Calif.) announced Tuesday she will not seek a sixth term in office and will retire from the Senate at the end of 2024, opening up her highly coveted seat for the first time in three decades.

Her announcement comes after growing concern over a decline in her cognitive health. Colleagues and journalists have reported interactions with the 89-year-old senator in which she showed signs of short-term memory loss — a stark contrast to the sharp, canny repertoire she has been praised for throughout her career.  

Feinstein — the longest-serving woman in the history of the Senate — has long been expected to retire at the end of her current term, having reduced her responsibilities in recent years. She turned down the position of Senate president pro tempore — which traditionally goes to the senior member of the majority party — last year, and stepped aside as the leading Democrat of the Senate Judiciary Committee in late 2020.

Despite Feinstein just recently announcing her retirement, a number of Democratic candidates have already declared their bids in California. Katie Porter announced her bid in early January, and a few weeks later, Adam Schiff followed suit. Schiff has already received an endorsement from Nancy Pelosi, who stepped down as House Speaker last year. Additionally, Barbara Lee is expected to announce her bid by the end of the month.

Beyond California, a changing of the guard may also be happening on the right, with Nikki Haley, 51, on Tuesday announcing her plan to take on Donald Trump, 76, in the 2024 GOP presidential race.

Feinstein told reporters she would make an endorsement “probably in a couple of months.” California’s other senator, Democrat Alex Padilla, said he would remain neutral. 

She and former Sen. Barbara Boxer made history in 1992 as the first women from California elected to the Senate. She has worked under five presidential administrations, and before presidents Barack Obama and Joe Biden took office, they served in the Senate alongside Feinstein.

During her tenure, she authored bills to ban assault weapons, protect unoccupied immigrant children, preserve undeveloped land and protect marriage equality, among countless others. She also holds the honor of having won the most votes in any single Senate election in history.

In the event that Feinstein retires before the end of her term, California Gov. Gavin Newsom would appoint her successor. However, Feinstein said in a statement she intends to accomplish as much as she can in her last year in the Senate.

“I campaigned in 2018 on several priorities for California and the nation: preventing and combating wildfires, mitigating the effects of record-setting drought, responding to the homelessness crisis, and ensuring all Americans have access to affordable, high-quality health care,” she said. “Congress has enacted legislation on all of these topics over the past several years, but more needs to be done — and I will continue these efforts.”