Cite as: 609 U. S.
(2026)
5
ALITO, J., dissentingregulate the mail. It holds the “general powers” to “adopt, amend, and repeal such rules and regulations, not incon- sistent with this title, as may be necessary in the execution of its functions under this title and such other functions as may be assigned to [it] under any provisions of law outside of this title.” 39 U. S. C. §401(2). Through this provision, Congress has “broadly empowered [the Postal Service] to adopt rules and regulations.” Postal Service v. Council of Greenburgh Civic Assns., 453 U. S. 114, 123 (1981). The Postal Service also possesses the power “to provide for the collection, handling, transportation, delivery, forwarding, returning, and holding of mail, and for the disposition of undeliverable mail.” 39 U. S. C. §404(a)(1).
If the question of the Postal Service’s power were before us in something other than the context of an ultra vires claim, the Government’s argument would present a difficult question. But here the question is different. In order to assert an ultra vires claim, the plaintiffs must show that the challenged regulation of envelopes here is “entirely ‘in excess”” of the power to govern collecting, handling, trans- porting, delivering, forwarding, and returning of mail. NRC v. Texas, 605 U. S., at 681. The same is true of the requirement to pass along information about each recipient of ballot mail. At the very least, the Postal Service did not act “contrary to a specific prohibition”” in enacting the rule. Ibid. (emphasis deleted).The plaintiff States resist these conclusions by invoking a highly technical provision tucked away in a corner of the Postal Reorganization Act of 1970. It concerns “nonmail- able matter,” a hodgepodge of items ranging from those that exceed the size and weight limits for certain classes of mail to fragrance-advertising samples. See 39 U. S. C. §3001. Under this provision, “proceedings concerning the mailabil- ity of matter under [chapter 30 of title 39] and chapters 71 and 83 of title 17 shall be conducted in accordance with [the APA].” §3001(m). But a lawsuit claiming the Postal Service