He issued a statement on November 13 on this topic:
It is erroneous and profoundly irresponsible to suggest that up to three million undocumented immigrants living in America are dangerous criminals - and threatening to immediately deport them only exacerbates the unprecedented angst and anger currently dividing our American community. It also appears to be a thinly-veiled pretense for a catastrophic policy of mass deportation that will tear apart families and weaken our economy. I implore President-elect Trump to reconsider and retract his preposterous statement.
I also want to assure the millions of people who are here pursuing and contributing to the California Dream, but lack documentation, that the State of California stands squarely behind you. State leaders will defend your due process rights and aggressively avail ourselves of any and all tools to prevent an unconscionable over-reach by a Trump administration in California. We will protect our people and prosperity.