Americans could be the next to be shunted off to foreign prisons if the Trump administration’s “shocking” treatment of a deported MS-13 suspect is allowed to stand, a federal appeals court said in a climactic ruling Thursday.

Judge Harvie Wilkinson, a 40-year veteran, said President Trump and his team have ignited an “incipient crisis” in refusing to un-deport Kilmar Abrego Garcia from the Salvadoran terrorist prison where he now languishes in what the judge cast as a dubious legal “limbo.”

And if it can happen to Mr. Abrego Garcia, the judge said, the Trump administration can do it to Americans — including an administration’s “political enemies.”

“The government is asserting a right to stash away residents of this country in foreign prisons without the semblance of due process that is the foundation of our constitutional order,” he thundered in a seven-page written ruling. “This should be shocking not only to judges, but to the intuitive sense of liberty that Americans far removed from courthouses still hold dear.”

He led a unanimous three-judge ruling by the 4th U.S. Circuit Court of Appeals, upholding Judge Paula Xinis’ order that the government reveal what steps it has taken to bring back Mr. Abrego Garcia.

Judge Wilkinson, a Reagan appointee, specifically singled out Judge Xinis for praise, calling her “a fine district judge.”

He urged President Trump’s team to back down from the “crisis” and bow to the courts, warning that the fight could do damage to both branches of government.

And he heaped blame on the administration for the situation.

“The Judiciary will lose much from the constant intimations of its illegitimacy, to which by dent of custom and detachment we can only sparingly reply. The Executive will lose much from a public perception of its lawlessness and all of its attendant contagions,” he said.

He added: “The Executive may succeed for a time in weakening the courts, but over time history will script the tragic gap between what was and all that might have been, and law in time will sign its epitaph.”

Mr. Abrego Garcia was an illegal immigrant to the U.S. and was ordered deported in 2019, though the immigration judge also found that he couldn’t be sent back to El Salvador in particular because he faced the possibility of violence.

The U.S. put him on a plane anyway on March 15.

The administration originally admitted that was wrong, but more recently officials have suggested the deportation was in fact allowable under the law, given his apparent membership in MS-13 and the government’s subsequent designation of the gang as a terrorist organization.

The MS-13 finding was established by an immigration judge in 2019, though Judge Xinis has said no such evidence has been presented in her court this year.

She has said Mr. Abrego Garcia’s March 12 arrest was “unconstitutional” and his deportation three days later was “unlawful.” She ordered the government to “facilitate” his return, and has demanded to know what steps have been taken toward that.

The U.S. says Mr. Abrego Garcia is now in the hands of El Salvador and is beyond America’s reach.

Salvadoran President Nayib Bukele has said the man is a Salvadoran citizen under his country’s control and he will not release him.

Judge Wilkinson, citing the Supreme Court’s ruling on the matter last week, said judges must give deference to a president’s conduct of foreign affairs.

But he said the government’s current answer is “to do essentially nothing.” It must make some attempt to try to earn Mr. Abrego Garcia’s “release from custody in El Salvador.”

“We are told that neither government has the power to act. The result will be to leave matters generally and Abrego Garcia specifically in an interminable limbo without recourse to law of any sort,” he said.

He was joined in his ruling by Judge Robert King, a Clinton appointee, and Judge Stephanie Thacker, an Obama pick.

Elected Democrats also have taken up the banner of Mr. Abrego Garcia.

Sen. Chris Van Hollen on Thursday defied the Salvadoran government by trying to reach the Terrorism Confinement Center, or CECOT, where Mr. Abrego Garcia is being held along with thousands of people El Salvador has deemed dangerous gang members.

The Maryland Democrat said soldiers stopped him 3 kilometers from the prison, saying they had been ordered to keep him out.

“We won’t give up until Kilmar has his due process rights respected,” Mr. Van Hollen told reporters afterward.

Salvadoran officials have said Mr. Van Hollen didn’t make a proper request for access to Mr. Abrego Garcia.

The White House says Democrats have chosen an odd martyr.

New documents released earlier this week show that Mr. Abrego Garcia’s wife, who is now begging for his return, accused him of beating her four years ago. Jennifer Vasquez said he punched and scratcher her, tore her clothes and left her bruised.

In a request for a protective order she said she was “afraid to be close to him.”

An immigration judge also found Mr. Abrego Garcia was a member of MS-13, citing a confidential police source report that identified him by his gang nickname and rank.

Judge Xinis has said no such evidence has been presented in her courtroom.

Judge Wilkinson said it didn’t matter so much at this point.

“Perhaps, but perhaps not,” he said. “Regardless, he is still entitled to due process.”

He said if Mr. Trump’s team is confident in his position, it should be willing to go through the full process.

• Stephen Dinan can be reached at sdinan@washingtontimes.com.