Nithya Raman, a progressive Los Angeles city councillor, has defeated incumbent mayor Karen Bass and is on course to become the first South Asian to lead America's second largest city.

Results called on Thursday put Raman on about 52 percent. The 45 year old, born in India and trained as an urban planner, overcame endorsements for Bass from California governor Gavin Newsom, former vice president Kamala Harris and former House speaker Nancy Pelosi. Her campaign drew backing from the Democratic Socialists of America, part of a wider midterm surge in which that movement claimed a role in hundreds of candidacies and ballot fights.

Raman had once endorsed Bass's re election before reversing course and filing just before the February deadline. In her victory speech she promised a more ambitious city, more affordable housing, better basic services and a different approach to homelessness that puts more medical teams with people living on the street. She also called for replacing the police chief over concerns about cooperation with federal immigration authorities.

Bass becomes the first Los Angeles mayor in more than two decades to lose a re election bid. Her term was dogged by criticism of the homelessness crisis and of the response to the deadly Palisades Fire, which began while she was overseas. In a statement she congratulated Raman and pledged a smooth transition, recalling her own historic win four years ago as the city's first Black woman mayor.

Raman inherits a city of more than 3.8 million people and the approaching 2028 Olympic Games. Delivery on housing and street homelessness will decide whether the progressive wave that lifted her, and earlier lifted New York mayor Zohran Mamdani, can govern at metropolitan scale.