One of the single biggest misconceptions about the commandeering doctrine that it is a direct application of the 10th Amendment. Indeed Judge Orrick’s decision in the Sanctuary City case repeatedly made this error. To the contrary, Justice Scalia explained in Part III.C of his opinion in Printz v. United States that commandeering is, at bottom, a limitation imposed by the Necessary and Proper Clause:

The dissent of course resorts to the last, best hope of those who defend ultra vires congressional action, the Necessary and Proper Clause. It reasons, post, at 941, that the power to regulate the sale of handguns under the Commerce Clause, coupled with the power to “make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers,” Art. I, § 8, conclusively establishes the Brady Act’s constitutional validity, because the Tenth Amendment imposes no limitations on the exercise of delegated powers but merely prohibits the exercise of powers “not delegated to the United States.” What destroys the dissent’s Necessary and Proper Clause argument, however, is not the Tenth Amendment but the Necessary and Proper Clause itself.^[13]

[13] This argument also falsely presumes that the Tenth Amendment is the exclusive textual source of protection for principles of federalism. Our system of dual sovereignty is reflected in numerous constitutional provisions, see supra, at 919, and not only those, like the Tenth Amendment, that speak to the point explicitly. It is not at allunusual for our resolution of a significant constitutional question to rest upon reasonable implications. See, e. g., Myers v. United States, 272 U. S. 52 (1926) (finding by implication from Art. II, §§ 1, 2, that the President has the exclusive power to remove executive officers); Plaut v. Spendthrift Farm, Inc., 514 U. S. 211 (1995) (finding that Article III implies a lack of congressional power to set aside final judgments).

When a “La[w] . . . for carrying into Execution” 924*924 the Commerce Clause violates the principle of state sovereignty reflected in the various constitutional provisions we mentioned earlier, supra, at 919, it is not a “La[w] . . . proper for carrying into Execution the Commerce Clause,” and is thus, in the words of The Federalist, “merely [an] ac[t] of usurpation” which “deserve[s] to be treated as such.” The Federalist No. 33, at 204 (A. Hamilton). See Lawson & Granger, The “Proper” Scope of Federal Power: A Jurisdictional Interpretation of the Sweeping Clause, 43 Duke L. J. 267, 297-326, 330-333 (1993). We in fact answered the dissent’s Necessary and Proper Clause argument in New York: “[E]ven where Congress has the authority under the Constitution to pass laws requiring or prohibiting certain acts, it lacks the power directly to compel the States to require or prohibit those acts. . . . [T]he Commerce Clause, for example, authorizes Congress to regulate interstate commerce directly; it does not authorize Congress to regulate state governments’ regulation of interstate commerce.” 505 U. S., at 166.

Chief Justice Roberts would revisit this discussion of “proper” in NFIB v. Sebelius.

As our jurisprudence under the Necessary and Proper Clause has developed, we have been very deferential to Congress’s determination that a regulation is “necessary.” We have thus upheld laws that are “‘convenient, or useful’ or ‘conducive’ to the authority’s ‘beneficial exercise.'” Comstock, 560 U. S., at ___ (slip op., at 5) (quoting McCul-loch, supra, at 413, 418). But we have also carried out our responsibility to declare unconstitutional those laws that undermine the structure of government established by the Constitution. Such laws, which are not “consist[ent] with the letter and spirit of the constitution,” McCulloch, supra, at 421, are not “proper [means] for carrying into Execution” Congress’s enumerated powers. Rather, they are, “in the words of The Federalist, ‘merely acts of usurpation’ which ‘deserve to be treated as such.'” Printz v. United States, 521 U. S. 898, 924 (1997) (alterations omitted) (quoting The Federalist No. 33, at 204 (A. Hamilton)); see also New York, 505 U. S., at 177; Comstock, supra, at ___ (slip op., at 5) (KENNEDY, J., concurring in judgment) (“[*560] It is of fundamental importance to consider whether essential attributes of state sovereignty are compromised by the assertion of federal power under the Necessary and Proper Clause . . .”).

…

No longer would Congress be limited to regulating under the Commerce Clause those who by some preexisting activity bring themselves within the sphere of federal regulation. Instead, Congress could reach beyond the natural limit of its authority and draw within its regulatory scope those who otherwise would be outside of it. Even if the individual mandate is “necessary” to the Act’s insurance reforms, such an expansion of federal power is not a “proper” means for making those reforms effective.

The Chief’s opinion here is somewhat opaque, but Justice Ginsburg’s dissent explains precisely what is at issue.

THE CHIEF JUSTICE cites only two cases in which this Court concluded that a federal statute impermissibly transgressed the Constitution’s boundary between state and federal authority: Printz v. United States, 521 U. S. 898 (1997), and New York v. United States, 505 U. S. 144 (1992). See ante, at 29. The statutes at issue in both cases, however, compelled state officials to act on the Federal Government’s behalf. 521 U. S., at 925-933 (holding unconstitutional a statute obligating state law enforcement officers to implement a federal gun-control law); New York, 505 U. S., at 176-177 (striking down a statute requiring state legislators to pass regulations pursuant to Congress’ instructions). “[Federal] laws conscripting state officers,” the Court reasoned, “violate state sovereignty and are thus not in accord with the Constitution.” Printz, 521 U. S., at 925, 935; New York, 505 U. S., at 176.

The minimum coverage provision, in contrast, acts “directly upon individuals, without employing the States as intermediaries.” New York, 505 U. S., at 164. The provision is thus entirely consistent with the Constitution’s design. See Printz, 521 U. S., at 920 (“[T]he Framers explicitly chose a Constitution that confers upon Congress the power to regulate individuals, not States.” (internal quotation marks omitted)).

New York v. United States involved commandeering of the states (through their legislators). Printz v. United States involved commandeering of state officials. The individual mandate in NFIB v. Sebelius involved what Randy Barnett referred to as the commandeering of the people.

Why is this relevant? The Court’s commandeering doctrine is premised on assessing the constitutionality of acts of Congress. However, with respect to the sanctuary city litigation, not all of the claims are premised on the validity of 8 U.S.C. 1373. Consider if the federal action came exclusively from an executive order, pursuant to Article II powers. That is, the President orders a state to provide his administration with some form of information, citing his Commander-in-Chief powers. Here, the necessary and proper clause would not be implicated. For the action to the unconstitutional, it would have to be based on the Tenth Amendment, standing by itself.

This analysis has shades of the facts of Medellin–wherein President Bush ordered Texas to comply with the Vienna Convention–though the Court resolved the issue based on the fact that the treaty was not self-executing. Indeed, the Tenth Amendment is mentioned nowhere in the decision.

This fact likely should not change the outcome of the cases, but courts should flag the fact that they are making new precedents with respect to executive-branch commandeering.