Sen. Bernie Sanders leads the Democratic presidential primary field in California, netting the support of 24% of voters, a poll conducted by the UC Berkeley Institute of Governmental Studies and released Thursday indicates.

That's an improvement in standing for the Vermont independent from September, the last time the poll was taken, when he was in third place with the support of 19% of voters.

Sen. Elizabeth Warren, D-Mass., and former Vice President Joe Biden saw their standings decline. Warren is now in second place with the support of 22% of voters; in September, she was at 29%. Biden is now at 14% in the poll; in September, he was at 20%. 

The poll also has some good news for South Bend (Indiana) Mayor Pete Buttigieg. In September, Buttigieg was at just 6%; in the latest poll, he now garners the support of 12% of voters. 

The survey was taken before Sen. Kamala Harris, D-Calif., dropped out of the race; she netted the support of 7% of voters. However, it did ask voters who their second choice preferences were. Reallocate votes based on those responses gives Sanders the support of 25% of voters; Warren, 24%; Biden, 17%, and Buttigieg, 13%. 

Sanders's strength in California, like his strength elsewhere, rests among younger voters. He is the first choice of 46% of voters between the ages of 18 and 29. He also sits atop the field when voters are queried about three different characteristics. A plurality of 28% of California Democratic voters say he is the candidate who can bring the right kind of change to Washington, 27% say he is the one who comes closest to sharing their values, and 28% say he is the candidate who best understands the problems of people like them.

Mark Camillo, the director of the Berkeley poll, told the Los Angeles Times the polling remains fluid. “Voters are struggling and not sticking with their candidates,” he said. “They are moving around from candidate to candidate.”

Biden retains a lead in national polling. In the latest RealClearPolitics aggregation of polls, Biden receives the support of 27.8% of Democratic primary voters while Sanders is at 15.6%, Warren is at 14.2%, and Buttigieg is at 11.4%.