The recent arrest of Palestinian activist and U.S. legal permanent resident Mahmoud Khalil, who played a prominent role in last year's Columbia University protests over the war in Gaza, has prompted questions about the limits of a green card.

A green card holder since 2024, Khalil was granted lawful permanent residency status in the U.S. But green card holders can lose their status and face deportation if they violate immigration law.

A federal judge on Wednesday extended efforts to halt Khalil’s deportation, and the New York resident remains in detention in Louisiana although he has not been charged with any crime.

It is not a criminal offense to disagree, even openly, with the U.S. government's policy or actions, and the Bill of Rights protects free speech and the right to assemble.

The why

Green cards can be revoked, New York-based immigration lawyer Linda Dakin-Grimm told VOA.

“It’s not that common, but it also isn’t rare. People lose their green cards most often when they’re convicted of crimes. … A green card is not citizenship. It’s seen as a privilege that you earn, but you can also lose it if you engage in conduct that is contrary to the conditions that green card holders live under,” she said.

Examples of crimes that can cause a green card holder can lose their status include aggravated felonies, drug offenses, fraud, or national security concerns such as ties to a terrorist group. Green card holders can also lose their status and lawful permanent residency status for being deemed a threat to national security.

If a green card holder is accused of a crime, their criminal case will go through the justice system. But the process to revoke their permanent status takes place in immigration court, where officials must present evidence to justify revoking a green card.

The how

Revoking a green card is a legal process that starts when the U.S. government determines that an individual has violated immigration laws.

The case can come to the government’s attention in different ways, either through a routine immigration check, law enforcement investigation, or whistleblower.

“It could theoretically be a whistleblower. Someone who has some information. … Could they call the State Department? Maybe. Could they call the ICE hotline? Maybe,” Dakin-Grimm said.

The Department of Homeland Security usually initiates the process. The green card holder will receive a document known as a Notice to Appear in immigration court or, in serious cases, they may be arrested and detained.

White House officials said Wednesday that Secretary of State Marco Rubio has the authority to revoke a green card or any visa if an individual’s activities in the United States “would have potentially serious adverse foreign policy consequences” to the country.

Rubio has said that Khalil’s case is not about free speech.

“No one has a right to a green card, by the way. … If you told us that’s what you intended to do when you came to America, we would have never let you in,” Rubio said on Wednesday. “If you do it once you get in, we’re going to revoke it and kick you out.”

The authority for the secretary of state to intervene in a case like Khalil’s stems from the Immigration and Nationality Act of 1952. A provision in the law allows the secretary of state to deem a non-citizen deportable if their presence or activities are believed to significantly harm U.S. foreign policy interests.

According to Khalil’s NTA, Rubio has made that determination.

Khalil has been ordered to appear in front of an immigration judge on March 27 at the Lasalle Detention Facility in Louisiana.

The court

In immigration court, the burden of proof is on the government; it must show the person violated immigration laws. In a case like Khalil’s, ICE attorneys will ask for deportation, but they will have to prove he is a threat to national security.

The green card holder can also present a defense.

In the criminal justice system, if a person cannot afford an attorney, the government must provide a public defender. In immigration court, however, immigrants have the right to their own attorney, but the government does not have to provide one. If immigrants cannot afford an attorney or cannot find one to represent them pro bono, they do will not have access to legal representation.

Dakin-Grimm says the process can sometimes go fast, but it is also complex.

In the immigration court system, the decision to revoke a green card is an administrative procedure conducted by the Department of Justice, under an office known as the Executive Office for Immigration Review.

“It’s kind of like the government is prosecuting a case, and the judge is also the government,” Dakin-Grimm said.

The outcome

If the immigration judge rules against the green card holder, they can appeal to the Board of Immigration Appeals (BIA).

And if the BIA agrees with the government, the green card holder can appeal to a Federal Court of Appeals. Although the case can end up at the U.S. Supreme Court, Dakin-Grimm says that rarely happens, mostly because the Supreme Court has complete discretion over the cases it chooses.

“Most people can’t afford to do this kind of legal work themselves. It’s just very, very expensive — you know, hundreds of thousands of dollars to take a case from the trial court level all the way to the Supreme Court,” she said. “But in the immigration space, you tend to see nonprofit agencies, law school clinics, working pro bono, working for free in significant cases like this.”

A final decision

If the green card is revoked and all appeals fail, the person is usually deported from the U.S. If the appeal is successful, the person keeps their green card and is allowed to stay in the country.

Dakin-Grimm said many green card holders think because it is called “permanent residency,” the status is actually permanent.

“But it’s only permanent as long as you follow the rules,” she said.

VOA White House correspondent Anita Powell contributed to this report.