Former Transportation Secretary Pete Buttigieg is posing an impeccable argument about due process to President Donald Trump, whose administration mistakenly sent Kilmar Abrego Garcia to a notorious prison in El Salvador and has defied a U.S. Supreme Court order to facilitate his return.

Buttigieg took the stage Tuesday at a town hall in Cedar Rapids, Iowa, and condemned the administration for its seeming indifference to due process, a constitutional right that affords individuals a fair legal proceeding before being deprived of life, liberty or property.

“I’m not a lawyer,” said Buttigieg. “You shouldn’t have to be to know that due process is afforded to everybody, because it is through that due process that our society can make decisions … about what happens to you if you are, in fact, held to be in violation of the law.”

“As, ironically, happened to the president himself when he went through probable cause, due process, jury — all that,” he continued, referring to Trump’s conviction last year in New York on 34 criminal charges of falsifying business records in a historic hush money trial.

Abrego Garcia had been living in the U.S. for roughly 14 years but was deported in March despite a federal protective order from 2019 declaring he couldn’t be sent back to his birth country due to fears of gang retribution. The Department of Justice has acknowledged his removal was due to an “administrative error.”

Trump, who recently said he isn’t sure whether he has a duty to uphold the Constitution, has justified the removal by claiming Abrego Garcia is an MS-13 gang member. The allegation, which the president appears to be basing on his tattoos, has never been proved in court.

“They’re saying, ‘Well, this guy, he’s a criminal,’” Buttigieg said Tuesday. “The whole point is that no one person — least of all, no one politician — gets to decide that you’re a criminal. Who decides? We have a process. We have laws. That’s what due process is.”

“You’re not a criminal because the head of the government of the country you live in says you’re a criminal,” he added. “Then, if that is the way it works, we are not a nation of laws.”

Trump launched mass deportations shortly after assuming office earlier this year and has since floated potentially sending some U.S. citizens to El Salvador as well. Senior adviser Stephen Miller recently confirmed the administration is “actively looking at” suspending habeas corpus.

Enshrined in the Constitution, habeas corpus attempts to shield people from unlawful detention by guaranteeing them the right to appear in front of a judge. On Tuesday, Buttigieg argued that lawmakers who have stayed silent on the matter “have more to fear from Trump” than they think.