The degree to which cities, states, and other local jurisdictions allow their police to serve as an arm of the federal immigration enforcement system has been the subject of debate for decades. On the one hand, everyone is interested in seeing the law upheld. On the other, cities and states have observed that a populace that's afraid that reporting a crime will bring the immigration authorities swooping into their communities tend to simply stop reporting crimes, which helps no one--and has led to many jurisdictions declaring themselves as so-called "sanctuaries."
At no time has this debate ever been as highly politicized as during the administration of Donald J. Trump, who vowed to end this practice during his campaign. In what was considered a major speech in September of 2016, Trump reportedly stated that he would "Block funding for sanctuary cities ... no more funding. . . .Cities that refuse to cooperate with federal authorities will not receive taxpayer dollars, and we will work with Congress to pass legislation to protect those jurisdictions that do assist federal authorities."
Trump apparently couldn't wait for Congress to enact legislation, and followed through by issuing an executive order called "Enhancing Public Safety in the Interior of the United States." This stated that sanctuary jurisdictions (as defined by the federal government, not the jurisdictions themselves) "are not eligible to receive Federal grants, except as deemed necessary for law enforcement purposes by the Attorney General or the Secretary. . . The Attorney General shall take appropriate enforcement action against any entity that violates 8 U.S.C. 1373, or which has in effect a statute, policy, or practice that prevents or hinders the enforcement of Federal law."
Not long after the order's issuance, various sanctuary jurisdictions sued over this prospective loss of funding, including Santa Clara County in California and the city of San Francisco.
In response, U.S. District Judge William H. Orrick, a federal judge in California, imposed a nationwide temporary injunction against the executive order. The basis for the injunction was his finding that lawsuits by Santa Clara County and San Francisco were likely to succeed when their merits are considered at a full court hearing, owing to the fact that an executive order is meant only to direct enforcement priorities for existing laws, while this order actually "impose[s] new conditions on federal grants."
The next step in this particular piece of litigation will be the government's Motions to Dismiss, tentatively scheduled for July 2, 2017.