What did Donald Trump do today?

He tried (and failed) to give himself power to unilaterally deport anyone for any reason.

Trump attempted to deport five Venezuelan nationals today, reportedly part of a much larger group, on the allegation that they were somehow connected to the criminal gang Tren de Aragua. In a proclamation issued today, Trump declared that the gang was "perpetrating, attempting, and threatening an invasion or predatory incursion against the territory of the United States." This was an attempt to invoke the only part of the Alien and Sedition Acts still on the books—the Alien Enemies Act of 1798.

Under the 227-year-old statute, written before there was a modern legal concept of citizenship or clearly established national borders for the United States, a president can detain or deport noncitizens when Congress has declared war, or when "any invasion or predatory incursion shall be perpetrated, attempted, or threatened against the territory of the United States." Its most famous application came as part of the legal framework allowing for the mass internment of Japanese-Americans during World War II. 

The law has never been invoked in peacetime, in part because the President has no inherent authority to unilaterally decide who may enter or remain in the United States. That power is given by the Constitution to Congress, which passes laws establishing an orderly and legal framework and empowers the executive branch to enforce only those laws.

As legal scholars were quick to point out today, if Trump's interpretation held, then he could deport any person of any immigration status on a whim simply by claiming they were part of a phony "invasion." The 1798 law does not require those detained or deported to have committed crimes, or entered the country illegally, or to have acted in any way against the United States. 

The Trump administration has offered no evidence that the targeted people are members of any gang, or that they have committed any crimes or status violations. If they had, it would be a routine matter to deport them using normal legal channels.

A federal judge issued a temporary restraining order prohibiting Trump from using the Alien Enemies Act to deport anyone for 14 days, finding that those targeted were likely to succeed in a legal challenge to their deportations. 

During a break in the hearing on the order today, the Trump administration apparently ordered planes carrying deportees to take off in an attempt to make the restraining order moot—in spite of the fact that the people involved will remain in the government's custody, meaning they posed no possible threat. The order that was issued required any such planes in the air to turn back.

Why does this matter?

• An executive branch that can't be trusted to respect the authority of the courts is a dictatorship in all but name.

• Presidents are not kings.