In his concurring opinion in United States v. Kebodeaux, the Chief wrote to talk a bit about Necessary & Proper and a federal police power. I think this is the first time since Sebelius that the Chief wrote about N&P.

Ordinarily such surplusage might not warrant a separate writing. Here, however, I worry that incautious readers will think they have found in the majority opinion something they would not find in either the Constitution or any prior decision of ours: a federal police power.

Roberts even took the time to criticize the Solicitor General’s position.

The danger of such confusion is heightened by the fact the Solicitor General adopted something very close to the police power argument, contending that “the federal government has greater ties to former federal sex offenders than it does to other members of the general public,” and can therefore impose restrictions on them even years after their unconditional release simply to “serve[ ] . . . publicprotection purposes.” Brief for United States 34–35.

…

Nevertheless, I fear that the majority’s discussion of the public-safety benefits of the registration requirement will be mistaken for an endorsement of the Solicitor General’s public-safety basis for the law. I accordingly concur in the judgment only

Citing Thomas’s concurring opinion in Morrison, the Chief stressed that there is no federal police power:

I write separately to stress not only that a federal police power is immaterial to the result in this case, but also that such a power could not be material to the result in this case—because it does not exist. See United States v. Morrison, 529 U. S. 598, 618–619 (2000) (“‘[W]e always have rejected readings of . . . the scope of federal power that would permit Congress to exercise a police power’” (quoting United States v. Lopez, 514 U. S. 549, 584–585 (1995) (THOMAS, J., concurring))).

Though there are no citations to Sebelius, Roberts cites language from McCulloch that he also cited in Sebelius (especially the “great and substantive and independent power” language):

Our resistance to congressional assertions of such a power has deep roots. From the first, we have recognized that “the powers of the government are limited, and that its limits are not to be transcended.” McCulloch, 4 Wheat., at 420–421. Thus, while the Necessary and Proper Clause authorizes congressional action “incidental to [an enumerated] power, and conducive to its beneficial exercise,” Chief Justice Marshall was emphatic that no “great substantive and independent power” can be “implied as incidental to other powers, or used as a means of executing them.” Id., at 418, 411; see also Gibbons v. Ogden, 9 Wheat. 1, 195 (1824) (“The enumeration presupposes something not enumerated”). It is difficult to imagine a clearer example of such a “great substantive and independent power” than the power to “help protect the public . . . and alleviate pub- lic safety concerns,” ante, at 8. I find it implausible to suppose—and impossible to support—that the Framers in- tended to confer such authority by implication rather than expression. A power of that magnitude vested in the Federal Government is not “consist[ent] with the letter and spirit of the constitution,” McCulloch, supra, at 421, and thus not a “proper [means] for carrying into Execution” the enumerated powers of the Federal Government, U. S. Const., Art. I, §8, cl. 18.

H/T Daniel Rice

Update: I wonder why the Chief has assigned Breyer both Comstock and Kebodeaux (Update-It’s been a long day, Roberts did not concur in Comstock), and has concurred separately in both. Oddly enough, Breyer’s opinion only has one citation to Comstock.

The Constitution, for example, makes few explicit references to federal criminal law, but the Necessary and Proper Clause nonetheless authorizes Congress, in the im- plementation of other explicit powers, to create federal crimes, to confine offenders to prison, to hire guards and other prison personnel, to provide prisoners with medical care and educational training, to ensure the safety of those who may come into contact with prisoners, to ensure the public’s safety through systems of parole and supervised release, and, where a federal prisoner’s mental condition so requires, to confine that prisoner civilly after the expiration of his or her term of imprisonment. See United States v. Comstock, 560 U. S. 126, 136–137 (2010).