“We need a strong anti-war senator, and she will play that role,” he said.

Lee is facing off against fellow Reps. Katie Porter and Adam Schiff, who have each already picked up key endorsements, from Sen. Elizabeth Warren (D-Mass.) and former House Speaker Nancy Pelosi (D-Calif.), respectively. As a leader in the House Progressive Caucus, Khanna’s endorsement could help Lee shore up progressive support in what’s expected to be a competitive — and expensive — race.

“I have respect for them,” Khanna said of Porter and Schiff, “but Barbara Lee 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 and stopping — trying to stop the war in Yemen and the war powers resolution.”

Khanna also noted that there are currently no African American women in the Senate, and Lee would fill that void. “Frankly, Jake, representation matters,” Khanna told CNN’s Jake Tapper.

“The other two are formidable candidates, but I think Barbara Lee is going to be very, very strong.”

Feinstein, the longest-serving woman in Senate history, announced her plans to forgo a 2024 bid last month. The 89-year-old’s retirement was widely expected, so much so that Porter and Schiff both launched their campaigns before she officially bowed out (though Schiff said his run was predicated on Feinstein’s retirement.)

California’s primary system allows the top two vote-getters to advance to the general election regardless of party, a system that’s likely to pit two Democrats against each other in November 2024 in a solidly blue state.