In a historic first, a federal judge on Thursday barred President Trump and his Administration from using an 18th Century law to deport a group of Venezuelan men now being held in a government detention center in a small town in Texas.

The 36-page ruling by U.S. District Judge Fernando Rodriguez, Jr.., of Brownsville, Texas, explicitly denied the Administration claim that the Alien Enemies Act of 1798 gives the President total power – with no review in court – to enforce that law against the foreign nationals covered by the ruling.

The judge also ruled that the law gives the President power to deport “enemy aliens” only if they have invaded the country as part of a foreign military force or organized army, and the judge concluded that that has not happened.

No other court has yet issued similar rulings since Trump claimed sweeping powers under a formal deportation proclamation issued March 15. Other courts that have heard challenges to the Trump order – including the Supreme Court — have issued only temporary rulings.

Judge Rodriguez, however, picked his way carefully through a variety of issues raised by the detained Venezuelan nationals, and not all of the opinion rejected claims by the Trump Administration.

The ruling explicitly protects only three individuals, identified only by their initials, as well as a “class” of other Venezuelans – the number is uncertain – being detained at the El Valle Detention Facility in Raymondsville, a town of about 10,000 people located at the very southern tip of Texas.

The judge barred the transfer of those individuals out of that detention center, and explicitly barred their deportation – if that were to be attempted under the President’s order or under the 1789 law. It does not bar deportation if done under the regular federal immigration laws, which give the government wide power to deport non-citizens. Judge Rodriguez pointed out explicitly that his ruling applied only to the 1789 law.

The decision is limited in those ways because of the kind of challenge the Supreme Court in a temporary order earlier this month has allowed under the 1789 law and because Judge Rodriguez’s judicial power in such cases only applies to the south Texas counties of Willacy and Cameron. The detention center is in Willacy County.

Even within those limitations, and even though the judge left some specific issues undecided, the ruling qualifies as a profound setback to the President and his Administration on one of the most controversial areas of the new national government’s actions during 100 days in office.

The judge’s decision goes well beyond what the Supreme Court itself has ruled so far under the old law, and is sure to be appealed by the Administration. Given how important the President and his aides regard their massive deportation campaign to be, government lawyers almost certainly will ask the Supreme Court to overturn Judge Rodriguez’s decision, without waiting for any further action in lower courts, and to rule during the Court’s current term, which is due to run through late June or early July.

The judge, who was named to the federal bench by President Trump seven years ago, during the first Trump term, based his ruling upon a wide-ranging inquiry into what the Alien Enemies Act meant, at the time of its enactment early in the nation’s Founding era – that is, between 1780 and 1820 — and how that Act has been understood since then.

Here are the main points that the judge decided:
• He rejected the Administration argument that the courts have no role to play in enforcing or judging presidential actions under the old law, but ruled that a judge’s power is limited to determining what the act’s text means and whether the document exceeds the President’s power.
• The Proclamation is illegal because it went beyond Trump’s power as President, since the Act allows the President to invoke its powers only when the U.S. has been invaded by “a military force or an organized, armed force with the purpose of conquering or obtaining control over territory,” or when “a military force or an organized, armed force” has entered the U.S. “to destroy property, plunder, and harm individuals” and then leaves the U.S. The judge ruled that the Trump proclamation, based upon claims of an invasion by a violent Venezuelan gang, does not show that either circumstance has happened.
• The judge – in one part of the ruling that favored Trump’s argument – decided that it was not necessary for there to be an actual war now occurring, or an imminent war on the horizon, before the President can invoke the Act’s powers. The Act describes war as only one option, not always necessary, for the act to be used against “alien enemies,” the judge found.

There were these other parts of the ruling that sided with Trump:
• The Proclamation does meet the Act’s requirement that a foreign government be involved, and the judge accepted Trump’s claim that the government of Venezuela is responsible for violent actions carried out in the U.S. by members of that Venezuelan gang.
• The judge found he had no authority to second-guess the President’s recital, in the document, of facts about activities of the gang or the specifics of any role in that activity by the government of Venezuela.
• The opinion took no position on how much advance notice the Venezuelan detainees are to be given that they have a right to show that they were not gang members and that they should be spared from deportation. Since the judge found flaws on other parts of the Proclamation, no ruling on this issue was necessary, according to the opinion. (The Supreme Court has decided that such notice is required, but it did not say how much time those covered by the document must be allowed. The Administration wants to give only 12 hours’ notice of a right to challenge and another 24 hours to actually begin a challenge.)
• The judge accepted, without reviewing its validity, the Administration argument that the Venezuelan gang members have committed serious crimes in the U.S. That, the judge said, is the kind of factual recital that the courts should not judge.

In general, the judge’s opinion appeared to go to significant lengths to show deference to the President’s power to decide how to react to foreign threats or to the conduct of individuals from other nations who commit serious crimes while in the U.S.

Judge Rodriguez, born in Texas and a lifelong resident, was a lawyer in private practice in Dallas before being appointed to the trial-level judgeship in Texas’s southern federal district. Before obtaining a law degree, he taught in an elementary school in Houston.