WASHINGTON (NEXSTAR) — The United States Supreme Court began hearing arguments Tuesday in a case that questions the validity of a rarely-enforced federal immigration law.

The law prohibits anyone to “come to, enter or reside” in the U.S. illegally. The punishment for violating it may be up to five years in federal prison.

The Trump administration made a bid to revive the measure after it was struck down by a lower court in 2018. The San Francisco-based 9th U.S. Circuit Court of Appeals deemed the law was a violation of the U.S. Constitution’s First Amendment guarantee of free speech.

Conservative Chief Justice John Roberts on Tuesday asked the attorney representing the U.S. government whether it would be illegal for a grandmother to tell her grandchild who was in the U.S. unlawfully, “I encourage you to stay.” Other justices questioned how charities and other organizations that work for immigrants’ rights would be affected.

“This isn’t about smuggling or trafficking, it’s just about encouraging,” said Mark Fleming, the attorney who represents a fellow lawyer who was charged with violating the law. “It would capture a teacher who says to an undocumented student you should stay here and be educated in the United States. It would cover a doctor who says to a patient you should stay here so I can treat your cancer.”

The case is centered around Evelyn Sineneng-Smith, a U.S. citizen who ran an immigration consultancy in San Jose, California, and was convicted of violating the law in 2013. She was also charged with mail fraud and was sentenced to 18 months in prison.

The Trump administration has maintained that the law is not meant to catch protected speech. Instead, the administration argued the law keeps people from soliciting illegal immigration.

The decision from the Supreme Court is expected by June.