The Supreme Court hears a case on Tuesday that has tremendous implications under the Trump administration.

On a summer day in 2010, 15-year-old Sergio Hernández Guereca was playing with three friends in a culvert of the Rio Grande that separates El Paso, Texas, and Juárez, Mexico. “The boys dared one another to run up a concrete incline and touch the barbed wire of the American border fence,” The New York Times reported. When U.S. Border Patrol Agent Jesus Mesa Jr. grabbed one of the boys, Hernández Guereca ran back toward Mexico. He made it across the unmarked borderline, but Mesa, some 60 feet away, shot him in the head anyway.

On Tuesday, the Supreme Court will hear oral argument in Hernández v. Mesa. The Trump administration will take the same position the Obama administration took: that the murdered boy’s parents cannot challenge the officer’s use of deadly force, even though the shots were fired on the U.S. side of the border, and that the Constitution in no way constrains such police shootings at the border. The Trump administration’s defense is that courts should simply mind their own business when border security is on the line.

These are the same arguments that the Trump administration made to defend its draconian travel and refugee ban aimed at Muslims. But as the Ninth Circuit made clear in denying the government a stay of a lower court’s suspension of the order, that’s not the Constitution our Framers designed. The president’s claim of “unreviewability … runs counter to the fundamental structure of our constitutional democracy.” (The administration is now asking the courts to ignore that executive order while it drafts a new one.)

With Hernández v. Mesa, the Supreme Court will have an important opportunity to reaffirm its core constitutional role of keeping the political branches in check, vindicating individual rights, and ensuring that no one is above the law. Given the president’s promise to increase federal power at the border, his claim that courts cannot review what he does, and his disrespect for judges that disagree with him, the Supreme Court’s role may now be more important than ever.

The fundamental question in Hernández v. Mesa is whether Hernández’s family can seek redress for this tragic abuse of power. Under the Constitution’s text and history, the answer is yes. The role of the courts in our system of separation of powers is to check official abuse of power and maintain the rule of law. There is no “border shooting” exception to these foundational principles.

When the Framers of the Constitution designed our system of government, they made the courts the frontline defense against violations of the Constitution’s guarantees. When a federal officer uses lethal force to kill an innocent civilian without justification, the ultimate responsibility to enforce the Constitution lies with the courts. Indeed, when Founders lobbied for a Fourth Amendment to check government misconduct, they viewed suits for damages such as Hernández’s as essential. An anti-Federalist essayist at the time argued that “no remedy has been yet found equal to the task of deterring and curbing the insolence of office, but a jury.”

For more than four decades, the Supreme Court’s so-called Bivens doctrine has allowed injured parties to sue for damages when their rights under the Fourth Amendment have been violated, recognizing that “damages have been regarded as the ordinary remedy for an invasion of personal interests in liberty,” and that for victims of police misconduct, “it is damages or nothing.” Conservative justices have long detested Bivens and have chipped away at it, but the fundamental principle remains that there must be some remedy available when federal officers violate the Constitution. Hernández—as well as Ziglar v. Abassi, an important case growing out of abuses committed by federal agents in the wake of 9/11 heard in the last days of the Obama administration—present the question of whether the Roberts Court will continue to chip away at the fundamental principle that individuals can go to court to remedy abuse of federal power, or whether it will reaffirm it.

When a six-justice Court heard oral argument in Ziglar last month, Justice Stephen Breyer and Chief Justice John Roberts sparred over the role of the courts in enforcing constitutional rights. Insisting on the need for courts to police the president and his subordinates, Breyer argued that “there’s no blank check for the President. And if there’s no blank check, that means sometimes they can go too far. And, if they have gone too far, it is our job to say that.” Roberts countered that the courts should not provide a “way of challenging national policy through damages actions against the individuals implementing it,” claiming that “we don’t want people forming policy to have to worry [that] they are going to have to … pay … if the policy is found infirm.” Expect the debate over access to courts to dominate the Hernández hearing, as well.

The government’s main argument is that judicial review, and, indeed, the Constitution itself, stops at the border. Hernández’s parents, the government maintains, cannot sue—even though Mesa fired his gun on U.S. soil—because their son was on the Mexican side of the border. Indeed, the government claims that the Constitution does not apply at all, even to an extrajudicial killing committed by an officer who fired within the U.S. This is an astounding claim. Even at the border, no U.S. officer is above the law. Yet the government’s argument would give federal agents a sweeping license to shoot to kill at the border, with no possibility of redress for victims and their families. That kind of unchecked, concentrated power is at war with the Constitution’s structure and its limits on abuse of government power.

This Supreme Court case will come down, as so many do, to Justice Anthony Kennedy. Nearly a decade ago, in the landmark 5-4 ruling in Boumediene v. Bush, his majority opinion concluded that even prisoners held at Guantanamo Bay, Cuba, on suspicion of terrorist activities could invoke the Constitution’s promise of access to the courts—specifically, the Suspension Clause’s guarantee of the writ of habeas corpus—to challenge the legality of their detention. Boumediene rejected the government’s claim that it could exercise unchecked power when detaining suspects at Guantanamo, refusing to give the government the power to “switch the Constitution on or off.”

If Kennedy follows these principles, he should insist that, even at the border, individuals can go to court to redress abuse of power by the government. With Trump promising bold action along the U.S.-Mexico border, the judiciary has a duty to ensure that he cannot turn the Constitution on or off at will.