On January 20, 2025, President Trump signed Executive Order 14,160. That Order attempted to end birthplace citizenship for children born in the United States to parents without permanent immigration status. The Supreme Court is now considering whether that order is constitutional, and Cato has filed an amicus brief in support of the Order’s challengers.

In our brief, we explain how the Executive Order contravenes the Fourteenth Amendment. The Fourteenth Amendment commands: “All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.”

The government argues that the phrase “subject to the jurisdiction thereof” in the Fourteenth Amendment requires political jurisdiction, not just regulatory jurisdiction. Political jurisdiction, in their view, demands allegiance to the United States–and therefore domicile–for citizenship. The government argues that children of parents without permanent immigration status cannot be domiciled in the United States, so they are not born citizens.

This argument does not comport with the ordinary public meaning of the Fourteenth Amendment; contemporaneous definitions, writings of the time, and court precedent show that “subject to the jurisdiction thereof” only required being under the United States’ authority. Because children of parents without permanent immigration status are under the authority of the United States and born in the United States, the Fourteenth Amendment grants them citizenship.

The ordinary public meaning of the text is corroborated by the Fourteenth Amendment’s purpose. In the past, the Court improperly limited this purpose in the Slaughter-House Cases and excluded those the Fourteenth Amendment meant to protect. We argue that this Court should support the broad purpose of the Fourteenth Amendment: to protect “all persons.” And the set of “all persons” includes the children of parents without permanent immigration status.

Our brief concludes with criticism of another amicus brief in this matter. Professor Ilan Wurman’s amicus brief provides a controversial account of the common law of birthright citizenship and an unusual application of originalism that pays insufficient attention to the Constitution’s original public meaning. We argue that a more adept deployment of originalism cannot support Professor Wurman’s conclusions.

In the end, the Fourteenth Amendment guarantees citizenship to all persons born in the United States. The President cannot ignore, rewrite, or abandon that promise by executive order. The Supreme Court should affirm the judgment below and issue a judgment that respects the rights of “All persons born … in the United States.”