“The provisions of state law at issue have the purpose and effect of making it more difficult for federal immigration officers to carry out their responsibiliti

“The provisions of state law at issue have the purpose and effect of making it more difficult for federal immigration officers to carry out their responsibilities in California,” Justice Department lawyers wrote. “The Supremacy Clause does not allow California to obstruct the United States’ ability to enforce laws that Congress has enacted or to take actions entrusted to it by the Constitution.”