Kilmar Abrego Garcia, a citizen of El Salvador legally resident in the United States since 2019, was deported to a Salvadoran prison last month in what has been widely deemed — including by lawyers at the Department of Justice — an “administrative error”.

Being sent to a maximum security prison by mistake is already the stuff of nightmares but, having acknowledged the error, the federal government has now compounded the problem by refusing to reverse course. Garcia remains in prison and the feds say that not only will they not bring him back, but that the courts have no authority to make them do so.

US District Court Judge Paula Xinis disagreed, and ordered that Garcia be returned to the United States. On appeal, the Fourth Circuit agreed. The administration has now appealed to the Supreme Court, which put the order on hold for the time being — though yesterday it granted Donald Trump the right to deport Venezuelan gang members using a law otherwise employed only during wartime.

When the full court hears the Garcia appeal, it is hard to see how the high court could fail to affirm the lower court ruling. An executive branch that can send someone to a foreign prison by accident and then refuse to correct the error is an executive wholly without limitation. It is the complete repudiation of one of the most basic parts of American governance: the separation of powers.

It is also, at the individual level, a gross miscarriage of justice. English jurist William Blackstone famously wrote that “the law holds that it is better that ten guilty persons escape than that one innocent suffer,” an idea which dates back to the Bible and other ancient texts. It has been a part of American jurisprudence since before independence. For the state to argue that an innocent can be punished and that the error cannot be rectified flies in the face of thousands of years of legal tradition.

Certain guarantees written into the Constitution from its earliest days would have worked to prevent this problem from progressing nearly so far. Federal authorities believed Garcia to be subject to deportation, but they never bothered to prove that he was. Had they proved that his status in the country had changed, deportation would have been entirely lawful. But they didn’t. They didn’t even try.

Legal process is not just a formality, but a guarantee against a government which is far more powerful than any one person. That is why people suspicious of the new, more powerful federal government which was created in 1788 demanded that a due process guarantee be added to the Constitution. It was, in 1791, and remains there. Going through the process of bringing the accused to court would have slowed down the deportation, but it would also have ensured that the feds got it right.

Without any process of law, any person can be treated in this way. Citizens and legal permanent residents generally can’t be deported; but if the government makes a mistake about someone’s legal status, there is no way to correct that without a hearing. No process means no real protection of law for any of us. Even if the government had been right and Garcia had been a dangerous gang member, he is owed that process because, without it, no one is safe from similar mistakes — or even false charges.

American liberty depends on power being separated among the branches. Congress has spent the past 100 years giving away its power, bit by bit, to the executive. But through it all, the judiciary remained independent and willing to sometimes serve as a check on executive overreach. Lots of countries have high ideals in their laws, but no means of enforcing them against the state. America’s separation of powers ensures that rights aren’t just words on a paper; instead, there is a means of protecting them.

US courts have gone too far at times, but this overreaction is a reminder of why the system demands that there be some check on the executive.