The Supreme Court debated during oral arguments Monday whether a criminal law meant to punish those who encourage illegal immigration could allow the government to punish anyone who helps undocumented immigrants.

A lower court had struck down a federal law that makes it a felony for someone who “encourages or induces” a person to violate federal immigration law, ruling that it infringed on the free speech protections of the First Amendment.

The U.S. appealed that ruling to defend the law, and justices are expected to issue a decision in the case before the conclusion of the term at the end of June.

Justice Brett M. Kavanaugh pointed out Monday that “it is a pretty common part of conversations” for people to discuss how an undocumented immigrant could remain in the country. Kavanaugh questioned whether a casual conversation about a topic such as that could violate the federal law, which carries a potential five-year prison term.

Brian H. Fletcher, the deputy solicitor general, said such conversations would not fall under the criminal law. Fletcher argued the court should read the law similarly to laws that punish “aiding and abetting” other crimes such as bank robbery, which have limits to them.

Kavanaugh pointed out that the law in this case is different because “the underlying offense is so different,” from other statutes that punish the aiding of a bank robbery, since immigration offenses are civil law violations.

“Just existing here is the underlying offense,” Kavanaugh said.

The case stems from the criminal prosecution of Helaman Hansen in 2017 for violations of the law at issue, as well as mail and wire fraud. The government said in court documents that Hansen operated a group called Americans Helping America Chamber of Commerce between 2012 and 2016 and falsely told undocumented immigrants they could obtain citizenship through adult adoption.

The government said more than 400 people participated in the program and Hansen’s organization collected more than $1.8 million.

Hansen argued in an appeal that the law should be thrown out because it would let the government prosecute speech about immigration that is otherwise protected by the First Amendment. A three-judge panel of the appeals court decided in Hansen’s favor, finding the law “overbroad and unconstitutional.”

Justice Neil M. Gorsuch called the court’s position “a little awkward” because it was considering whether to allow conduct by Hansen that effectively defrauded immigrants.

“I don’t think anyone could say he has been chilled from speaking,” Gorsuch said.

Gorsuch and Justice Amy Coney Barrett pointed out the law has existed since the 1950s and been amended several times without facing any First Amendment challenges.

Justices Ketanji Brown Jackson and Sonia Sotomayor raised concerns the law as it stands is infringing the First Amendment, since people may be discouraged from discussing immigration issues because they are afraid of consequences under the law.

Jackson pointed out that just because nonprofit organizations currently advocate feeding and housing undocumented immigrants, the law might be discouraging others from doing the same.

“We don’t know how many other people would have engaged in that kind of, you know, speech and action if it weren’t for this law,” Jackson said.

Sotomayor got into an extended exchange with Fletcher, questioning whether the government could prosecute family members of undocumented immigrants for saying they wished a grandmother could stay in the country.

When Fletcher said he did not think the statute would apply, Sotomayor pushed back.

“Stop qualifying with ‘think,’ because the minute you start qualifying with ‘think,’ then you’re rendering asunder the First Amendment,” Sotomayor said. “People have to know what they are allowed to talk about.”

Fletcher responded that the court could write an opinion that emphasized the law has similar limits to other “aiding and abetting” or “solicitation” statutes.

Esha Bhandari, the attorney for Hansen, argued that concepts like “aiding and abetting” and “solicitation” have specific legal meanings that the court shouldn’t write into the statute on its own.

Bhandari said Congress amended the law multiple times, and removed a requirement that the government prove a defendant knew they were committing a crime, and the government wants the Supreme Court to read that back into the law.

Congress could have passed a law with limits that comply with the First Amendment, Bhandari said. “Congress did not do that here. And Congress could do so if this Court were to hold that this law simply doesn’t say what the government says,” she said.

Bhandari pointed to outside organizations, such as immigration attorneys and journalists who said the government has used investigations under the law to target their speech around immigration.