California’s 2016 primary fell in June after Donald Trump and Hillary Clinton were already the presumptive nominees. The measure, backed by California’s majority Democrats and endorsed by Secretary of State Alex Padilla, passed the state Senate on the final night of the year’s legislative session. The Latest on a bill moving California's presidential primary to March (all times local):

California lawmakers have voted to move the 2020 presidential primary to March to give the nation's most populous state more influence in choosing nominees. SACRAMENTO, Calif. — The California Assembly has voted to move the 2020 presidential primary to March to give the nation’s most populous state more influence in choosing nominees. The nation’s most populous state is also one of the most expensive to campaign in, and California has been marginalized in previous elections even when it held earlier primaries, including in 2008. Brulte also suggested moving the state's primary to March could benefit Sen. Kamala Harris, the state's junior U.S. senator who's been mentioned as a potential candidate. But the Democratic field in 2020 appears wide open, and a March contest in California could provide an opportunity for candidates able to raise enough early money to campaign in the state’s expensive media markets. “The candidates are going to be forced to campaign in California.”

The effect of California moving its primary from June remains uncertain. The measure is expected to come up for final votes before the Legislature adjourns for the year on Friday.
California passes a bill that will move the primaries to March near Super Tuesday.