Second, they want local jail authorities to honor ICE “detainers.” These are administrative requests (not court orders) to local jails to hold certain aliens—suspected of being undocumented—for 48 hours. Even if there are no charges pending against them, ICE agents want them held until they can pick them up with an eye to deportation. There are two problems with the detainers. First, they don’t come with funding. (According to figures submitted by Santa Clara County in this case, complying with detainers can cost it nearly $8 million a year.) Second, holding anyone—citizen or not—without probable cause or a court order is unconstitutional; and the feds don’t pay the cost of lawsuits either.

Orrrick’s tone is polite; but boiled clean, he reaches three conclusions. First, even the government doesn’t know what the order means and thus localities can’t comply even if they want to; second, the order is a naked grab for executive power—usurping not only the Tenth Amendment powers of states, but also the Article I spending power of Congress; and third (just as with the claim that the travel-ban order is actually a Muslim ban), Trump’s own intemperate words have sealed the order’s fate.

The judge notes that the two plaintiffs—the City of San Francisco and the nearby Santa Clara County—depend on federal funds, among other things, “to provide medical care, social services, and meals to vulnerable residents, to maintain and upgrade roads and public transportation, and to make needed seismic upgrades.” The executive order gives the Attorney General and the Secretary of Homeland Security the authority to designate any locality as a “sanctuary jurisdiction” and then “take appropriate enforcement action” to block some or perhaps even all of this funding.

This threat of catastrophic revenue loss is designed to force the counties to enforce federal immigration law. This is unconstitutional in no fewer than three ways. First, the Supreme Court has repeatedly said that the federal government can’t directly require states to enforce federal law. Second, the Supreme Court has also said repeatedly that the feds can’t use the threat of funding cutoffs so large that they “coerce” states into complying with conditions that would be unconstitutional if made as direct orders. And third, the court has said that only Congress can impose conditions on federal grants. The president cannot, with a stroke of his own pen, transfer this core power to himself or his appointees.

To make matters worse, no locality would know how to follow the order if it wanted to, the opinion notes. The order prescribes penalties for jurisdictions that “willfully refuse to comply” with federal immigration law; but the government admitted in court that “the Attorney General and Secretary of Homeland Security have not yet figured … out” what those words mean. In addition, Orrick writes, “at least as of two months ago, the Secretary himself stated that he ‘do[esn’t] have a clue’ how to define ‘sanctuary city.’”