During a session attended by the President, a notable moment unfolded as a former attorney for Donald Trump, now serving as a senior Department of Justice official, encountered a sharp retort from the Chief Justice of the Supreme Court. The exchange occurred after the attorney made a quip about a “new world” that supposedly necessitates an overhaul of birthright citizenship laws.

As the proceedings began, U.S. Solicitor General D. John Sauer advocated in front of the predominantly conservative court, arguing that the current era demands a reinterpretation of constitutional law to align with the Trump administration’s immigration policies. These policies are outlined in an executive order aimed at safeguarding the “meaning and value of American citizenship.”

The 14th Amendment’s citizenship clause declares that all individuals born or naturalized in the U.S., with few exceptions such as the children of foreign diplomats, are citizens. This provision remains a point of contention, particularly in the context of the Trump administration’s stance on birthright citizenship, as noted by sources like the ACLU and other legal experts.

In the case of Trump v. Barbara, the administration argued that the almost automatic granting of birthright citizenship has led to various issues, including national security threats and the rise of “birth tourism.” This term describes a practice where foreigners visit the U.S. to give birth, thereby securing citizenship for their children. President Trump has controversially labeled these children as “anchor babies.”

Chief Justice John Roberts expressed skepticism regarding the significance of the “birth tourism” issue, questioning its relevance to the legal arguments. Despite seeking clarification, the court did not receive specific data on the prevalence of this phenomenon.

Justice Roberts inquired, “Do you have any information about how common that is or how significant a problem it is?” Yet, a concrete response was not forthcoming during the session.

“No one knows for sure,” Sauer answered, before referring to “media reports” and estimates of over a million examples from China alone, with hundreds of “birth tourism” companies, and some Russian elite “hot spots” in Miami.

WATCH: Chief Justice John Roberts asks the U.S. solicitor general about birth tourism:

D. John Sauer: “We’re in a new world now … where 8 billion people are one plane ride away from having a child who’s a U.S. citizen.”

Roberts: “Well, it’s a new world. It’s the same… pic.twitter.com/G68qGH1YfA

— PBS News (@NewsHour) April 1, 2026

It was then that Sauer flirted with living constitutionalism, remarking, “But of course, we’re in a new world now, as Justice Alito pointed out to you, where 8 billion people are one plane ride away from having a child as a U.S. citizen.”

“Well, it’s a new world, but it’s the same Constitution,” Roberts fired back.

Seemingly stung, Sauer had to pause a moment before he could respond with, “It is.”

“And as Justice Scalia said, I think in the case that just Alito was referring to, you’ve got a constitutional provision that addresses certain evils, and it should be extended to reasonably comparable evils. You said that about statutory interpretation. I think the same principle applies here,” the solicitor general finished his thought.

Sauer insisted, as he did in his brief, that the “children of aliens temporarily visiting the United States or of illegal aliens” cannot have birthright citizenship when their parents lack “a permanent domicile.” That, the solicitor general said, is a far cry from granting citizenship to “freed slaves and their children” after the Civil War.

Later on, when Justice Brett Kavanaugh was questioning ACLU attorney Cecillia Wang, he said the whole ballgame boiled down to whether the court said her reading of precedent was the right one. The ACLU’s brief emphasized that the 1898 case of United States v. Wong Kim Ark “correctly interpreted” the citizenship clause to “include children of foreign nationals without regard to parental domicile.”

Wong, the son of Chinese immigrants with “permanent domicil and residence,” was barred from reentering the U.S. under the Chinese Exclusion Act despite having been born here. Ultimately, the Supreme Court affirmed that Wong was an American citizen, under the 14th Amendment.

While it was unclear which way Kavanaugh was leaning, he was already envisioning how the case might end in the ACLU’s favor, to the attorney’s apparent delight.

“I think Mr. Sauer acknowledged, and you mentioned this in your opening, that if we agree with you on how to read Wong Kim Ark, then you win,” Kavanaugh said. “That could be just a short opinion, right, that says ‘the better reading is respondents’ reading, the government doesn’t ask us to overrule, affirmed’?”

“Yes,” Wang quickly replied, to audible laughter in the courtroom.

That joyful sentiment was not shared by the president.

“We are the only Country in the World STUPID enough to allow ‘Birthright’ Citizenship!” Trump posted.