Washington CNN  — 

Democratic Rep. Ro Khanna of California announced Sunday that he won’t enter the competitive Democratic primary to fill retiring Sen. Dianne Feinstein’s senate seat in the Golden State, electing to endorse Democratic Rep. Barbara Lee instead.

“I have concluded that despite a lot of enthusiasm from Bernie [Sanders’] folks, the best place, the most exciting place, action place, fit place, for me to serve as a progressive is in the House of Representatives,” Khanna told CNN’s Jake Tapper on “State of the Union.”

“And I’m honored to be co-chairing Barbara Lee’s campaign for the Senate and endorsing her today. We need a strong anti-war senator and she will play that role.”

The Democratic field to fill Feinstein’s seat also includes Reps. Adam Schiff and Katie Porter, who announced their bids earlier this year. Khanna had previously expressed interest in running for the vacant seat.

Lee, who announced her bid last month, is a member of the House Democratic leadership, serving as co-chair of the Democratic Steering Committee, and she was the former chair of the Congressional Black Caucus.

Throughout her time in Congress, Lee has served as the co-chair and whip of the Progressive Caucus. And before coming to Washington, she spent several years serving in the California state legislature.

If elected, Lee would be the sole Black female senator serving in the Congress and only the third in US history.

Lee, Khanna said Sunday, is a “unique voice. She was the lone vote against the endless war in Afghanistan. She stood up so strongly against the war in Iraq. She worked with me in trying to stop the war in Yemen, the War Powers Resolution. And frankly, Jake, representation matters. We don’t have a single African American woman in the United States Senate.”

Currently, Lee is at a disadvantage compared to her well-funded rivals. She had just $52,000 in cash on hand entering 2023, according to FEC filings, while Schiff had more than $20 million stockpiled at the end of the year and Porter had more than $7.4 million.

Under California’s primary system, all candidates run on the same ballot, with the top two candidates, regardless of party, advancing to the general election.

This story has been updated with additional information.