The executive order restricts automatic citizenship for babies born to parents who aren't citizens or lawful, permanent residents.

California sued Trump's first administration 123 times. Trump lost two-thirds of those cases, but experts warn that California could have a tougher go this time.

California joins New Jersey, Massachusetts, Colorado, Connecticut, Delaware, Hawaii, Maine, Maryland, Michigan, Minnesota, Nevada, New Mexico, New York, North Carolina, Rhode Island, Vermont, and Wisconsin,