Sen. Dianne Feinstein hasn’t said if she intends to seek another term in 2024 — but the competition to succeed the oldest member of Congress is escalating.

Reps. Ro Khanna and Katie Porter are fielding entreaties to jump into the race, and Rep. Adam Schiff has publicly declared he is exploring a run. Rep. Barbara Lee is spending the holidays mulling her next move. Three hopefuls have contacted former Sen. Barbara Boxer to seek her advice, marking the incipient stages of a fierce fight between California Democrats for a seat that has not been open for a generation.

“They’re starting to call me to get ready for what is a massive campaign – truly, massively expensive and hard-fought,” Boxer said. “It will be a very crowded field.”

Schiff fired the first salvo last month by openly admitting his long-known interest in the seat, telling a Los Angeles television station that, after his House leadership bid fizzled, he would “consider running for the Senate if Senator Feinstein decides not to run for reelection.” Schiff also met with Feinstein to inform her of his intentions, according to two people familiar with the exchange.