Alito, J., dissenting
new law, Congress passed “transition rules [that] delayed the onset of the Secretary’s obligation to begin making arrests as soon as covered aliens were released from criminal custody.” Nielsen, 586 U. S., at ___ (slip op., at 21). If the Executive had possessed the discretion to decline to enforce the new mandates in light of “resource constraints,” see ante, at 8, those transition rules would have been entirely “superfluous.” Nielsen, 586 U. S., at ___ (slip op., at 21).
Despite this clear text and background, the majority now claims that the President’s “enforcement discretion” survived these mandates, ante, at 7, but there is no basis for that conclusion. Certainly it is not supported by the cases it cites. They either underscore the general rule that the Executive possesses enforcement discretion, see Reno v. American-Arab Anti-Discrimination Comm., 525 U. S. 471, 490–491 (1999), or pair that general rule with the observation that the States cannot limit the Government’s discretion in pursuing removal, see Arizona, 567 U. S., at 396, 409. Nothing in those decisions is inconsistent with Congress’s power to displace executive discretion, and the fact that “five Presidential administrations” sometimes neglected the mandates is likewise irrelevant. See ante, at 8. As I have stressed before, the Executive cannot “acquire authority forbidden by law through a process akin to adverse possession,” Biden v. Texas, 597 U. S., at ___ (dissenting opinion) (slip op., at 15), and that is true even if the adverse possession is bipartisan.
B
The events that gave rise to this case began on January 20, 2021, when the Acting Secretary of DHS issued a memorandum with “enforcement priorities” for the detention and removal of aliens found to be in this country illegally. This memorandum prioritized: (1) aliens “whose apprehension” implicated “national security,” (2) aliens not present “before November 1, 2020,” and (3) aliens due to be released
