Citing the 1952 Immigration and Nationality Act, Trump-appointed U.S. Secretary of State Marco Rubio determined last month that Khalil could harm American foreign policy interests and should be deported for his "otherwise lawful" speech and activism.
Comans said that she did not have the authority to overrule a secretary of state. The judge denied a motion by Khalil's lawyers to subpoena Rubio and question him about the "reasonable grounds" he had for his determination under the 1952 law.
The judge's decision came after a combative 90-minute hearing held in a court located inside a jail complex for immigrants surrounded by double-fenced razor wire run by private government contractors in rural Louisiana.
Khalil, a prominent figure in the pro-Palestinian student protest movement that has roiled Columbia's New York City campus, was born in a Palestinian refugee camp in Syria, holds Algerian citizenship and became a U.S. lawful permanent resident last year. Khalil's wife is a U.S. citizen.
For now, Khalil remains in the Louisiana jail where federal authorities transferred him after his March 8 arrest at his Columbia University apartment building some 1,200 miles (1,930 km) away. Comans gave Khalil's lawyers until April 23 to apply for relief before she considers whether to issue a deportation order. An immigration judge can rule that a migrant cannot be deported because of possible persecution in a home country, among other limited grounds.
In a separate case in New Jersey, U.S. District Judge Michael Farbiarz has blocked deportation while he considers Khalil's claim that his arrest was made in violation of the U.S. Constitution's First Amendment protections for freedom of speech.
As Comans adjourned, Khalil leaned forward, asking to address the court. Comans hesitated, then agreed.
Khalil quoted her remarks at his hearing on Tuesday that nothing was more important to the court than "due process rights and fundamental fairness."
"Clearly what we witnessed today, neither of these principles was present today or in this whole process," Khalil said. "This is exactly why the Trump administration has sent me to this court, a thousand miles away from my family."
The judge said her ruling turned on an undated, two-page letter signed by Rubio and submitted to the court and to Khalil's counsel.
Khalil's lawyers, appearing via a video link, complained they were given less than 48 hours to review Rubio's letter and evidence submitted by the Trump administration to Comans this week. Marc Van Der Hout, Khalil's lead immigration attorney, repeatedly asked for the hearing to be delayed. Comans reprimanded him for what the judge said was straying from the hearing's purpose, twice saying he had "an agenda."
Comans said that the 1952 immigration law gave the secretary of state "unilateral judgment" to make his determination about Khalil.
Khalil should be removed, Rubio wrote, for his role in "antisemitic protests and disruptive activities, which foster a hostile environment for Jewish students in the United States."
Rubio's letter did not accuse Khalil of breaking any laws, but said the State Department can revoke the legal status of immigrants who could harm U.S. foreign policy interests even when their beliefs, associations or statements are "otherwise lawful."
After Comans ended the hearing, several of Khalil's supporters wept as they left the courtroom. Khalil stood and smiled at them, making a heart shape with his hands.
Khalil has said criticism of the U.S. government's support of Israel's military occupation of Palestinian territories is being wrongly conflated with antisemitism. His lawyers told the court they were submitting into evidence Khalil's interviews last year with CNN and other news outlets in which he denounced antisemitism and other prejudice.
His lawyers have said the Trump administration was targeting him for protected speech, including the right to criticize American foreign policy.
"Mahmoud was subject to a charade of due process, a flagrant violation of his right to a fair hearing and a weaponization of immigration law to suppress dissent," Van Der Hout said in a statement after the hearing.
The American immigration court system is run and its judges are appointed by the U.S. Justice Department, separate from the government's judicial branch.
