The Supreme Court handed the Trump administration a major border-security win Thursday, ruling 6, 3 that the federal government can turn back asylum seekers at the U.S., Mexico border before they physically step onto American soil. The decision reverses the Ninth Circuit, revives the legal foundation for "metering," and settles a question that has divided courts for nearly a decade: does walking up to a port of entry make you an arrival?

The answer, Justice Samuel Alito wrote for the conservative majority, is no.

The ruling in Mullin v. Al Otro Lado holds that the Immigration and Nationality Act requires physical entry, not attempted entry, before asylum eligibility attaches. A migrant standing on the Mexican side of the line has not "arrived in the United States," and border officers are under no obligation to inspect or process a claim until that person is on U.S. soil. As Newsweek reported, lower-court injunctions that had blocked the practice are now effectively undone.

Alito's majority: words mean what they say

The majority opinion turned on a plain-language reading of the statute. National Review noted that Alito wrote: "In ordinary speech, no one would say that a person 'arrives in' a place, for example, a house, a city, or a country, before the person enters that place." He compared the situation to a guest who knocks on a front door: the guest has not arrived in the house.

That analogy did double duty. It dispatched the Ninth Circuit's reasoning, which had treated approaching a port of entry as equivalent to arriving, and it undercut the dissent's claim that the ruling would push migrants toward illegal crossings. Alito, Fox News reported, downplayed those concerns directly, noting that metering "does not permanently bar any alien from arriving in the United States and then applying for asylum."

The majority also stressed institutional restraint. The Court's role, the opinion stated, is limited to "interpreting and applying the law", not designing immigration policy from the bench.

The dissent: Sotomayor reads from the bench

Justice Sonia Sotomayor, joined by Justices Elena Kagan and Ketanji Brown Jackson, delivered a rare bench dissent. She called the ruling a "tragic" extinguishing of the ideals symbolized by the Statue of Liberty, AP News reported, prompting an unusual public rebuttal from Alito himself.

Sotomayor argued the decision creates exactly the incentive structure it claims to prevent:

"This Court has previously recognized that immigration statutes and procedures should not be construed to 'create a perverse incentive to enter at an unlawful rather than a lawful location. Yet, the majority's construction does exactly that.'"

She also accused the majority of fixating on a single word. "The Court's illogical interpretation is driven almost entirely by a fixation on a single word: 'in,'" she wrote. In her view, the ruling allows the executive branch to "circumvent all these mandatory procedures by having U.S. immigration officers stand at the border and physically block noncitizens from setting a foot onto U.S. soil."

It is worth pausing on what the dissent actually concedes. Sotomayor does not dispute that Congress wrote the statute. She does not claim the text says something different from what Alito reads. Her objection is that the plain meaning produces results she dislikes, and that the executive branch might use the authority the statute provides. That is a policy argument dressed in judicial robes, and the majority treated it accordingly.

Metering: the policy behind the case

The case traces back to 2017, when the Trump administration began pressuring Mexico to help regulate migrant arrivals at ports of entry. Breitbart reported that the practice, known as metering, limits the number of asylum seekers processed at the border each day. The Trump administration later expanded it across all southern ports of entry during its first term.

The lawsuit was filed nearly ten years ago by immigrant-rights group Al Otro Lado and thirteen asylum seekers. They argued that metering violated asylum law and forced migrants into dangerous conditions in Mexico. Lower courts agreed, and the Ninth Circuit barred the government from turning people back.

Thursday's ruling wipes that away. And the administration is not shy about what comes next. DHS General Counsel James Percival told Newsweek:

"We had to go all the way to SCOTUS to vindicate the principle that an alien is not 'in the United States' until he is, in fact, in the United States."

Percival added: "We have yet AGAIN been vindicated by the Supreme Court. This decision opens up an important tool to continue securing our southern border."

The administration told the Court during arguments that it wants the flexibility to reinstate turn-backs if border numbers spike, a signal that metering may return in full force, depending on conditions at the southern border.

A pattern at the high court

Thursday's decision fits a broader pattern this term. The Court recently issued another 6, 3 ruling allowing border agents to deny re-entry to green card holders accused of crimes, a decision that also drew sharp objections from the liberal bloc.

The immigration docket is far from finished. The justices are also weighing whether ICE can hold criminal immigrants without bond hearings, another enforcement case that cuts along the same ideological lines.

And the term still has major decisions ahead on birthright citizenship, presidential firing power, and other politically charged questions. As the Court works through that remaining docket, the 6, 3 conservative majority continues to define the boundaries of executive authority on immigration, often over furious objections from the three liberal justices.

The numbers behind the fight

The scale of the asylum system helps explain why the ruling matters so much. At the end of 2025, roughly nine million people worldwide were awaiting asylum decisions. The U.S. immigration system alone carried a backlog nearing four million cases.

Those numbers make the dissent's position operationally untenable. If every person who walks up to a port of entry is entitled to full processing regardless of capacity, the system collapses under its own weight. Metering exists precisely because the alternative is chaos, or the kind of open-border conditions that defined the worst months of the Biden era.

The metering concept, notably, did not originate with President Trump. The practice was first implemented under the Obama administration, later expanded by Trump, and then ended under Biden. That bipartisan lineage makes the progressive fury over Thursday's ruling harder to take seriously. When Obama used the same tool, no one called it a betrayal of the Statue of Liberty.

What the ruling does, and does not, do

The decision does not abolish asylum. It does not bar anyone from applying. It holds that the right to apply attaches once a person is physically present in the United States, not before. Border officials retain discretion over how many people they process at a given port on a given day, and the executive branch retains the authority to manage that flow.

Future legal challenges may focus on implementation, how metering is applied, whether it creates unlawful delays, and what conditions migrants face while waiting in Mexico. Immigrant-rights groups are certain to press those arguments in lower courts.

But the central legal question is settled. The Ninth Circuit's expansive reading of the statute is gone. And the principle that the Court's role is to apply the law as written, not to rewrite it for preferred policy outcomes, got another strong endorsement from the conservative majority.

The linked opinion in case No. 25-5 runs to considerable length, but the core holding is simple enough to fit on a bumper sticker: you are not in the United States until you are in the United States.

Congress wrote the law. The Court read it. If progressives want a different result, they know where the Capitol is.