On June 30, 2026, the Supreme Court issued its opinion in Trump v. Barbara, No. 25-365, regarding the scope of birthright Citizenship under the Fourteenth Amendment and related statutes. Neutral Principles had filed its first amicus brief in that case, arguing that the text and history of the phrase “subject to the jurisdiction" of the United States unambiguously covered all those present in the United States absent a law or treaty whereby the United States renounced its jurisdiction over a class of persons (such as ambassadors). Having not done so regarding undocumented immigrants or their children born in the United States, the United States had jurisdiction over such children and they were citizens by birth. The Supreme Court held that such children are indeed U.S. citizens by birth. The opinions can be seen here. We will post more analysis of this decision and the lengthy opinions shortly.

On May 21, 2026 Neutral Principles filed a merits-stage amicus brief in the U.S. Supreme Court in support of petitioners in Suncor Energy v. County Commissioners of Boulder County. No. 25-170.  The amicus brief, written by Legal Advisory Board member Professor Eugene Volokh and founding Board of Directors member Erik Jaffe argues that lawsuits seeking to impose climate-change liability on oil companies based on their First Amendment speech, association, and petitioning activity regarding climate change science and policy violates the First Amendment and would run afoul of the dormant Foreign Commerce Clause. The brief emphasizes the importance of robust debate on important scientific and policy questions, even when a scientific “consensus” might deem that debate resolved.  The case will be argued next term. You can read the Full Neutral Principles brief here, and see the full docket with links to other briefs here.

On April 3, 2026, Neutral Principles filed an amicus brief in the U.S. Court of Appeals for the D.C. Circuit in Perkins Coie LLP v. United States Department of Justice, and the consolidated law-firm cases, Nos. 25-5241, -5265, -5277, and -5310. The amicus brief argues that the original public meaning of the text, supported by the history, of the First Amendment and of the “executive Power” vested in the President encompassed a broad view of the freedoms protected by the First Amendment and a narrow scope of executive discretion to act in ways that abridge such freedoms. Specifically, proponents of the First Amendment viewed past abuses of discretion by the Crown as abridgments of the freedoms of speech and the press and were loathe to grant the executive similar powers. The past examples against which the First Amendment was written to guard included discretionary licensing regimes that favored some speakers and viewpoints and punished others, removal of judges and attorneys who took positions against the government, and viewpoint discriminatory application of the taxing power via the Stamp Acts.  The challenged executive orders in this case, punishing law firms that took positions and represented persons disfavored by the administration, thus violate the original public meaning of the Constitution. 

Neutral Principles was joined by additional amici the Center for Individual Rights and Protect the First Foundation. You can read the full brief here. ​

On February 26, 2026, Neutral Principles filed an amicus brief in the U.S. Supreme Court in Trump v. Barbara, No. 25-365, advocating for a strict adherence to the well-understood original public meaning of the Fourteenth Amendment’s Citizenship Clause. The brief argues that the words and combined phrase “subject to the jurisdiction” of the United States were well known at the time of the Fourteenth Amendment, referred to the lawful authority and power of a government’s laws and courts over, at a minimum, persons within the territorial bounds of that government, and thus presumptively covered all persons born in the United States.  And while jurisdiction over classes of persons could be ceded by law or treaty, as in the case of diplomatic immunity, that has not been done with regard to persons born of foreign parents present (lawfully or otherwise) in the United States. It also notes that abdicating such jurisdiction on a prospective basis, though constitutionally permissible, would carry a severe cost of ceding law enforcement authority over such persons, contrary to the frequent exercise of such authority by the present and past administrations alike.
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You can read the full brief here and find all of the other filings in the case here.