Barbara Boxer

Sen. Dianne Feinstein, 89, the oldest member of the U.S. Senate, has not yet said whether she will seek a sixth term when her current one expires in January 2025. She has said she will announce her decision this spring. Persistent questions about her mental acuity have fueled calls, including from the Los Angeles Times editorial board, for her to retire rather than run again.

Even without a formal announcement, the race to succeed her is already underway. Democratic Reps. Katie Porter and Adam Schiff have launched campaigns, and Rep. Barbara Lee has told colleagues she intends to run as well, with more candidates possibly to follow. Given California's Democratic lean, the eventual winner is expected to come from within the party, and observers anticipate a contest defined more by personal contrasts and intra-party rifts than sharp policy differences, echoing the centrist-versus-progressive tensions that shaped Feinstein's own career. The outcome will hinge heavily on whether Feinstein ultimately steps aside.