In 2012 President Obama announced the policy known as DACA (Deferred Action for Childhood Arrivals), which provided lawful status to about 1.5 million people brought to the United States illegally as kids. In 2014, he announced a follow-up policy known as DAPA (Deferred Action for Parents of Americans and Lawful Permanent Residents). While there was no significant challenge to DACA, a group of states challenged the legality of DAPA. Cato filed amicus briefs in their support at the district court, circuit court, and Supreme Court. Throughout the litigation, Cato maintained that it supported DAPA as a policy matter—we were joined by several law professors along the way—but the president lacked the authority to pursue this change in the law unilaterally.

After Justice Antonin Scalia died in 2016, the Supreme Court split 4–4 on Texas v. United States, leaving an injunction against DAPA in place. After President Trump was elected, he announced DAPA’s termination and, eventually, a suspension of DACA. A number of plaintiffs, individual and institutional, argued that ending DACA was unlawful. In other words, the administration was required to continue enforcing DACA even if it thought it was unconstitutional (let alone if it simply wanted to reverse a policy determination). Several lower courts blocked the president from winding down DACA, holding that the executive branch failed to justify its actions. The Supreme Court has granted review to determine whether the rescission of DACA was lawful.

Having sat out the lower-court litigation, Cato has gotten back involved, with an amicus brief joined by Prof. Jeremy Rabkin and co-authored by Prof. Josh Blackman (also a Cato adjunct scholar). Once again we support DACA as a policy matter—and say so explicitly on the front cover—but, as with DAPA, the president can’t change the laws unilaterally. The appealed rulings are wrong because DACA goes beyond executive power under the Immigration and Naturalization Act (INA). But even if the Court declines to reach that holding, then the INA itself violates the nondelegation doctrine as applied here.

First, two general INA provisions can’t bear the weight of this foundational transformation of immigration policy, while DACA can’t be supported by any “implicit” congressional acquiescence either. Moreover, it shouldn’t matter if Congress has stood by idly when previous presidents exercised materially different deferred-action policies. These arguments are sufficient to confirm the attorney general’s conclusion that DACA is unlawful. But even if the Court disagrees—or declines to reach that issue—the executive branch still provided adequate grounds to justify rescission.

That is, second, the attorney general reasonably determined that DACA is inconsistent with the president’s duty of faithful execution. Admittedly, his letter justifying the rescission is not a model of clarity. But it need not be. This executive-branch communication provides, at a minimum, a reasonable constitutional objection to justify DACA rescission. Specifically, it invokes the “major questions” doctrine, which is used “in service of the constitutional rule” that Congress cannot delegate legislative power to the executive branch, as Justice Neil Gorsuch described in his dissent in Gundy v. United States this past June. Here, the Court should accept the executive’s determination of how to avoid a nondelegation problem: by winding down a discretionary policy.

Cato scholars support comprehensive immigration reform, of which a DACA-type policy is only one part. But we also have an interest in preserving the separation of powers that maintains the rule of law at the heart of the Constitution’s protections for individual liberty.

No president can unilaterally rewrite laws—in conflict with the laws passed by Congress and in ways that go beyond constitutionally authorized executive power. Nor does the president acquire more powers when Congress refuses to act, no matter how shameful the congressional inaction is. Such unlawful executive actions both set back prospects for long-term reform and, more importantly for a lawsuit, weaken the rule of law.

The separation of powers prevents the president from expanding his own authority. Those same dynamics ensure that a subsequent president can reverse his predecessor’s unlawful actions that self-aggrandize executive power. Reversing the lower-court rulings in Department of Homeland Security v. Regents of the University of California, which argument the Supreme Court will hear November 12, would restore the immigration debate to the political process—exactly where it belongs.