LOS ANGELES—Vice President Kamala Harris and her husband, Douglas Emhoff, will head to Las Vegas Saturday after spending three days campaigning in Southern California and Sacramento.

Ms. Harris arrived Wednesday afternoon at Los Angeles International Airport from Joint Base Andrews near Washington and was greeted by L.A. Mayor Karen Bass and Reps. Judy Chu (D-Monterey Park), Grace Napolitano (D-Norwalk), and Maxine Waters (D-Los Angeles).

On Thursday, she flew to Sacramento where she spoke at a California Legislature Democratic Caucus reception and a campaign reception before returning to Los Angeles later in the day.

While in Southern California Wednesday, Ms. Harris attended a late-afternoon campaign fundraiser in Manhattan Beach where she told attendees she intends “to be on the road full time for the next 10 months to do what needs to be done.”

With former President Donald Trump on track to gain the Republican nomination for president a third time, and a rematch with the Joe Biden-Kamala Harris Democratic ticket later this year, Ms. Harris told supporters at the home of Moez Kaba and Bjorn Lundberg that “everything is at stake this election.”

“It is about the foundation of democracy and our democratic principles,” she said. “It is a fight for our nation and what we stand for.”