Daniel Lurie, the San Francisco mayor, relied on powerful tech executives and his own low-key approach to help his liberal city escape a rush of federal agents.
President Trump said he had halted a planned federal deployment of immigration agents to the city. It was not clear what that meant for the rest of the Bay Area.
The San Francisco district attorney said in an interview that she came up with the strategy after seeing federal agents repeatedly roughing up people in Los Angeles and Chicago.
The ability of states to arrest federal officers is murky, and without much legal precedent, according to the dean of University of California, Berkeley School of Law.
U.S. Customs and Border Protection agents are being sent to a U.S. Coast Guard base in Alameda, Calif., ahead of an immigration operation in the San Francisco region.