Government lawyers, in a new race through the federal courts, are claiming an unlimited power for President Trump – an authority intended for use only in wartime that has been used just three times during actual wars.

That is an authority, granted by Congress 236 years ago, that would allow Trump to deport immediately any non-citizen that he deems to be dangerous to the U.S. As his lawyers define the power, Trump could use it with no review in the courts, leaving the targeted individuals with no remedy. Protections now given to non-citizens now in the U.S. by immigration laws would be bypassed completely.

This new legal saga, one of scores developing in the courts since Trump resumed the Presidency eight weeks ago, began Friday in a federal trial court in Washington, D.C., and swiftly developed over the weekend. There was some drama, too: the judge at one point ordered planes carrying some individuals away to return to the U.S. while the case on their fate unfolds.

At the center of the case are five young men, citizens of Venezuela but now in this country, who have been designated by Trump as “enemy aliens” under an 1789 federal law after government officials labeled them as members of a violent criminal gang, Tren de Aragua. (Tren in English means “Train.” The gang, centered in Venezuela but operating in other countries, had its origin among men in a prison in the Venezuelan state of Aragua. It has been designated a terrorist group by U.S. officials.)

Four of the five men in the case explicitly deny membership in the gang, and some claim they have been harmed or threatened by the gang. They are identified in court papers only by their initials. They are represented by liberal legal advocacy organizations, including the American Civil Liberties Union.

The law behind the President’s move to swiftly deport them is the Alien Enemies Act, passed by Congress at a time when some lawmakers feared war with France and acted out of suspicion that French spies were operating inside the U.S. It has been used previously only during declared wars: the War of 1812 and World Wars I and II.

The Act allows the President, when the U.S. is formally at war with another nation or when another nation has engaged in a “hostile” invasion or “predatory incursion” (long understood as military attacks), to round up “enemy aliens” living here and rapidly deport them, with few significant limitations on timing or with only sparse court review.

When Trump was running for election last year, he said several times that he would invoke those powers to deal with what he called an “invasion” of the U.S. by violent individuals, especially along the southern U.S. border. On Friday night, he signed a formal “proclamation” claiming the power against those living here who were designated as part of the Venezuelan-based gang.

Trump could not claim that the nation was at war with another other nation, but he did assert that the gang had infiltrated this country by an “invasion or predatory incursion” and that it amounted to a foreign nation itself because of the freedom he said the gang has to operate in Venezuela. In some legal circles, including some conservative judges and legal academics, the nation is now said to be experiencing an “invasion” because of the government’s inability to stop a surge in unwanted immigration.

Based on Trump’s public statements about invoking the act, the President and other government officials were sued early Saturday, even before the formal proclamation was made public that afternoon. The case is being pursued before the chief judge in the nation’s capital, District Judge James E. Boasberg.

The judge promptly blocked deportation of the five Venezuelans for 14 days while he reviewed the dispute, then later expanded his order to protect all non-citizens who were potentially threatened with deportation under the old 18th Century law. A hearing on next steps is set for next Friday.

Even before Judge Boasberg had finished his actions on Saturday, Trump Administration lawyers swiftly asked the federal appeals court in Washington to set aside the restrictions or to order Judge Boasberg to drop the case. The Administration’s main arguments are that the restrictions are unconstitutional restrictions on the President’s power over foreign affairs and national security, that the courts – including Judge Boasberg – have no role to play under the Alien Enemies Act, and that other judges will follow Judge Boasberg’s lead and issue orders severely restraining the President’s powers to protect the American people from foreign threats.

The lawyers for the Venezuelans are basically making five points against Trump’s claim to power under the 1789 law:
• The Venezuelan gang is not a foreign government, and there is a government of Venezuela that the U.S. formally recognizes.
• There has been no invasion or military-style “incursion” by any individuals or group, and the law only applies when there is a genuine threat of an actual war.
• The Venezuela-based gang is not an army of the kind that engages in hostile military action; rather, it is merely a criminal gang.
• Federal immigration laws enacted by Congress, especially in 1952, set up a comprehensive system governing the procedures the government must follow before acting to deport any non-citizen living in the country, even if they are in the country illegally. The old 1789 law must yield to those procedures.
• What Trump is attempting to do also violates the old law itself, because that law can lead to deportation only for a non-citizen who will not leave voluntarily; the President’s action closes off that option.
The Alien Enemies Act has seldom been at issue before the Supreme Court, although there was an important decision there in 1948 (Ludecke v. Watkins). By a 5-4 vote, the Court ruled that World War II had not formally ended at that point so the government could continue to rely on the old law, although it also ruled that courts may hear challenges to enforcement of the law in specific cases if that does not intrude heavily on the President’s war powers. Both the majority and the dissenting Justices focused on the law as being closely keyed to the existence of an actual war.

In the Venezuelan’s case, the next steps will be additional legal filings with Judge Boasberg in the coming week and likely action by the federal appeals court on the Trump Administration plea to shut down the case entirely. Eventually, the case may go, even in a preliminary way, to the Supreme Court.