An American constitutional crisis brews in a Central American prison

A test of American constitutional democracy is unfolding in an unlikely place: a shadowy Central American prison system.

U.S. President Donald Trump has done numerous things in his second term that have been deemed authoritarian or illegal, and he's threatening to do more.

But there's one line he hasn't crossed, at least not yet. He has not wilfully, clearly, defied a court order, crossing the Rubicon into a constitutional no man's land where rules don't apply.

That's what makes the case of Kilmar Abrego Garcia more than a murky tale about one man's banishment to different El Salvadoran prisons, including, initially, an infamous gulag-like anti-gang facility.

Much is unclear about the man himself.

A court decision this week acknowledged allegations that Abrego Garcia is a low-level gang member, beset by a history of domestic abuse allegations. Or was he actually escaping the gangs of his native El Salvador, to build a life as a construction worker in Maryland, with an American wife and child?

Of his alleged gang ties, a court decision this week said: "Perhaps, but perhaps not."

What's clearer about this case is that it has the potential to open the floodgates to the constitutional crisis under Trump that many have feared and predicted.

The administration is being ordered by the courts to at least try to follow the law. In other words, make an effort to get Abrego Garcia back; file the proper paperwork; and seek to deport him again — but legally.

The response from Trump's team, so far? Outright mockery. The administration was reprimanded by lower courts and ridiculed them. The Supreme Court weighed in, and now, for the first time, Trump may be defying the high court.

He clearly relishes this fight: instead of talking about massively unpopular tariffs, Americans are now talking again about migration — a popular issue for Trump.

But members of the legal community, and not just liberals, insist this is bigger than migration, or any single case, and transcends normal domestic politics.

"We're fast approaching our first real moment of truth," said former Yale Law School dean Harold Hongju Koh, a constitutional law professor and a legal adviser to the State Department during the Obama presidency. 

"Will the Supreme Court let him get away with a transparent sham? If not, will Trump openly defy a court order?" Koh wrote in an email to CBC News. "And will the American public accept the shocking claim that Trump has the power to ship innocents like Abrego García — and even American citizens — to offshore hellholes without even a fig leaf of due process?"