Amicus Brief in Trump v. Barbara: An Originalist Defense of Birthright Citizenship

Abstract

For nearly all of the first 235 years under the Constitution, the citizenship of every child born in the United States to alien parents, with immaterial exceptions, was a given. Then, in 2025, the Trump administration changed course. The administration’s approach is not originalist, and their conclusion is not correct.

First, two originalist principles of interpretation are essential to weighing the evidence: that the Citizenship Clause has the same meaning it had at adoption, and that the ordinary meaning communicated to the ratifying public by its words—not the private intent of drafters—controls. The Government’s post-ratification evidence, beginning 15 years after the drafting of the Fourteenth Amendment, cannot amend its original text. Nor can a private letter change its public meaning.
Second, applying those principles, the balance of evidence is clear. The ordinary meaning of “jurisdiction” at ratification was the power to govern. Because transient and unlawful aliens present here are governed by the United States, they are “subject to the jurisdiction” of the United States, and their children born here are citizens as a result.

Third, preratification evidence supports that meaning. The Constitution’s use of “citizen” tracked in relevant part the common-law meaning of “subject.” Even a child born in England to an alien owing “momentary and fleeting” allegiance while traveling through England to commit treason was a subject. Congress and early American courts continued to apply that logic, and the leading antebellum case held that children of transient aliens are citizens.
Fourth, the debates on the Civil Rights Act of 1866 and the Fourteenth Amendment offer little support for the Government’s reading. To the contrary, members of Congress asked if the children of “temporary sojourners,” the Roma people (pejoratively called “Gypsies” at the time), and Chinese immigrants (whose status implicated the category of “illegal” immigration) would be citizens—and for each, the answer was yes.

Last, the Government’s logic would have made aliens out of the children of slaves, many of whom entered “unlawfully” by virtue of being trafficked here after a federal ban. And it would resurrect the allegiance-without-protection rationale of Dred Scott v. Sandford, 60 U.S. (19 How.) 393 (1857), which the Fourteenth Amendment forever repudiated. That cannot be correct.

Keywords: Citizenship, Originalism, Legal History, Immigration, Asian-American History, History of Roma, Reconstruction, Fourteenth Amendment