California Gov. Gavin Newsom hasn’t endorsed any of the remaining Democratic presidential candidates but his wife on Friday said she’s backing Massachusetts Sen. Elizabeth Warren in Tuesday’s primary.

“Now more than ever, women need a champion in the White House — someone who will stand up for working moms, fight for our seats at the tables of power, protect our health care and reproductive choice, and lift up the underappreciated and often invisible contributions that women make daily to society,” Jennifer Siebel Newsom said in a statement. “There is no person better equipped to fight for us than Elizabeth.”

Gavin Newsom has not endorsed another candidate since his chosen candidate, California Sen. Kamala Harris, left the race in December.

California holds its primary on Tuesday alongside 13 other states, and it is the biggest delegate prize in the Democratic primary calendar. Warren has not campaigned frequently in the state but plans to return Monday for an event in Los Angeles.

Vermont Sen. Bernie Sanders, her progressive rival, is leading in polls and has appearances in San Jose and Los Angeles on Sunday.

Siebel Newsom, a documentary filmmaker focused on gender equity, has chosen the title “first partner” rather than the traditional first lady because it’s gender neutral. Since her husband assumed office last year, Siebel Newsom has launched an equal pay initiative and pushed Newsom to adopt family-friendly policies including eliminating the tax on diapers and expanding access to paid family leave.

“Jennifer’s efforts to break the mold and reshape the First Partner’s office to advocate for equal pay and women’s representation will empower women and girls not just in California but around the country and the world,” Warren said in a statement.