In the final opinion of a landmark term, an unusual coalition of justices coalesced to ratify the Biden administration’s nixing of the Migrant Protection Protocols, a policy colloquially known as “Remain in Mexico.”

The ruling comes down the same week that 53 bodies were found in the back of a truck that crossed the border from Mexico. The deaths are a macabre reminder of an immigration landscape that has generated both human tragedy and political crisis for the Biden administration. 

The policy in question required some asylum seekers at the southern border to be sent back to Mexico to wait while their immigration status was resolved. Under the MPP, the Trump administration returned more than 70,000 migrants to Mexico. In 2021, the Border Patrol reported more than 1.7 million encounters with migrants along the southern border.   

The case, Biden v. Texas, centered on whether President Biden had the authority to end the program, which he moved to do on his first day in office, prompting state lawsuits that drove the case to the Supreme Court. In a five-to-four vote, Chief Justice Roberts joined Justices Stephen Breyer, Elena Kagan, Brett Kavanaugh, and Sonia Sotomayor in handing the president a legal victory. 

Undoing the policy has proved to be difficult. Lower courts have found the administration’s rationale for doing so insufficient, and questioned whether cancellation was even possible, “concluding that the return policy was mandatory so long as illegal entrants were being released into the United States.”

The statute in question reads: “In the case of an alien … who is arriving on land … from a foreign territory contiguous to the United States, the [secretary] may return the alien to that territory” pending appropriate procedure. While the law appears to grant executive discretion, judges have held that if the government does not detain migrants, it must redirect them. 

The majority rejects that reading, pointing both to the sense of the text and the implications that such a statutory understanding would unduly constrain the executive branch’s ability to conduct foreign policy. The majority warns of the “the danger of unwarranted judicial interference in the conduct of foreign policy.”  

Constitutionally, the president has a broad mandate when it comes foreign policy. The chief justice writes, “By interpreting section 1225(b)(2)(C) as a mandate, the Court of Appeals imposed a significant burden upon the Executive’s ability to conduct diplomatic relations with Mexico.”  

That ability is particularly salient here, because MPP required negotiations with the Mexican government. 

The majority likewise held that the technicalities of appeal and administrative procedure did not tie the administration’s hands, as lower courts had claimed. In finding for the government on two fronts, the opinion cuts a broad swath of executive discretion when it comes to immigration policy.

In a concurrence, Justice Kavanaugh lifted his eyes from the statutory thicket toward “the larger policy story behind this case,” which he tells as “the multi-decade inability of the political branches to provide DHS with sufficient facilities to detain noncitizens who seek to enter the United States pending their immigration proceedings.”

In dissent, Justice Samuel Alito notes that if an alien is “not clearly and beyond a doubt entitled to be admitted,” the alien “shall be detained for a [removal] proceeding.” He accuses the court of “looking the other way” in allowing the Department of Homeland Security to “simply release into this country untold numbers of aliens who are very likely to be removed if they show up for their removal hearings.”

A separate dissent from Justice Amy Coney Barrett began with a decision to which nary a justice signed on: “I agree with the Court’s analysis of the merits—but not with its decision to reach them.” In her view, the high court should never have heard the case. She would “tread more carefully” and allow the case to stew further in the lower courts.

Even as the court’s decisions over the past two weeks have chartered a constitutional new era, the release of Biden v. Texas marked a very human changing of the guard, as it drew the curtain on Justice Stephen Breyer’s time on the court and marked the dawn of Justice Ketanji Brown Jackon’s tenure. 

In a letter to the President, Justice Breyer wrote that “it has been my great honor to participate as a judge in the effort to maintain our Constitution and Rule of Law.”