The Supreme Court decided Trump v. Barbara, No. 25-365, on June 30, 2026, resolving whether the Fourteenth Amendment’s citizenship guarantee extends to children born on American soil to parents who are here illegally or on a temporary visa. The Court split 5–4 on the constitutional question, with Chief Justice Roberts joined by Justices Sotomayor, Kagan, Barrett, and Jackson holding that birth on U.S. soil confers citizenship. That result will get its own treatment elsewhere. What deserves attention now is a separate opinion by Justice Brett Kavanaugh, concurring in the judgment and dissenting in part, that has nothing to do with immigration policy and everything to do with the future of the Second Amendment.
A Statutory Concurrence, A Constitutional Gift
Justice Kavanaugh did not join the majority’s constitutional holding. He would have resolved the case on narrower statutory grounds under 8 U.S.C. § 1401(a), reasoning that Congress currently grants citizenship to children born here but retains the power to amend that statute. On the constitutional question itself, he sided with the dissenters: the Fourteenth Amendment’s citizenship clause, in his view, does not itself guarantee citizenship to the children of birth tourists or of aliens unlawfully present. As he put it, “the constitutional issue is not straightforward, much as we might want it to be.”
To get there, Kavanaugh had to grapple with United States v. Wong Kim Ark, 169 U.S. 649 (1898), which read the “subject to the jurisdiction thereof” clause to guarantee birthright citizenship subject to four narrow exceptions: children of foreign sovereigns and their ministers, children born on foreign public ships, children of enemies within and during hostile occupation, and children of tribal members. Every court to consider the question, he wrote, has treated those four exceptions as closed — fixed as of 1868, with no room for new ones. Kavanaugh rejected that reading, and the doctrine he reached for to reject it is the same doctrine that governs the Second Amendment.
”Not a Closed Set Trapped in Amber”
Here is the passage that matters, and it deserves to be read in full:
“The Constitution is an enduring document, and its principles were designed to — and do — apply to modern conditions and developments. The original constitutional principles do not change absent a constitutional amendment. But the relevant principles — both the rules and the exceptions alike — must be faithfully applied not only to circumstances as they existed in 1789, 1791, and 1868, for example, but also to modern situations that were unknown or unanticipated by the Constitution’s framers. Stated otherwise, the meaning of the rules is constant; only their application to new situations presents a novelty.”
Kavanaugh then reached for examples from three different amendments. Courts apply Fourth Amendment reasonableness to car searches, though cars did not exist in 1791 or 1868. Courts apply First Amendment protections to the internet, though the internet did not exist in 1791 or 1868. And, in his words, “in Second Amendment cases, this Court applies the amendment to semi-automatic handguns even though those did not exist in 1791 or 1868,” citing District of Columbia v. Heller, 554 U.S. 570 (2008). From there he drew the governing principle: “This Court’s constitutional precedents do not treat the 1791 or 1868 exceptions as a closed set trapped in amber,” citing United States v. Rahimi, 602 U.S. 680 (2024).
Why Heller’s Silence on “Semi-Automatic” Matters
That citation to Heller is worth dwelling on. Heller arose from Dick Anthony Heller’s attempt to register a revolver in the District of Columbia — a simple wheel-gun, not a semi-automatic pistol. The word “semi-automatic” appears nowhere in the Heller opinion. Yet Justice Kavanaugh, like Justices Alito and Thomas before him in other writings, reads Heller as protecting semi-automatic handguns as a matter of course. That is not a strained inference. It is the necessary consequence of holding that the Second Amendment’s guarantee travels forward in time rather than freezing at the technology of 1791 or 1868.
What This Means for Viramontes and Grant
The timing is not incidental. The Court granted certiorari the same week in Viramontes v. Cook County, Illinois, No. 25-238, and Grant v. Higgins, No. 25-566, consolidated cases asking whether the Second Amendment protects semi-automatic rifles like the AR-15. A justice who has just gone on record — in an opinion having nothing to do with guns — rejecting the idea that constitutional protections are “trapped in amber,” and who has specifically identified semi-automatic handguns as protected arms under Heller, has told litigants exactly how he approaches the “in common use” and “bearable arms” questions the Court will face this coming term. The logic runs in one direction only: if the amendment already reaches handguns Madison never saw, it reaches rifles he never saw either. I have argued for years that the AR-15 fight would be won on precisely this ground. Justice Kavanaugh just wrote the roadmap into a birthright citizenship case, and any court reading Viramontes and Grant will not be able to pretend it isn’t there.
This article is based on analysis by Professor Mark W. Smith, constitutional attorney and Host of the Four Boxes Diner 2nd Amendment channel. Watch the original video here. This does not constitute legal advice.