On January 20, 2025, President Donald Trump issued an executive order purporting to limit birthright citizenship to children who have at least one parent who is a citizen or is lawfully admitted for permanent residence. Several states, including the state of Washington, and individual immigrants challenged the order as a blatant violation of the Fourteenth Amendment, which states that “[a]ll 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.” According to the Trump Administration, the children of noncitizen parents without lawful status, as well as the children of noncitizen parents whose status is “lawful but temporary,” are not “subject to the jurisdiction” of the United States and are not birthright citizens. The United States District Court for the Western District of Washington granted a preliminary injunction blocking the order, and the Trump Administration appealed to the United States Court of Appeals for the Ninth Circuit.

CAC filed an amicus brief supporting the states on behalf of an ideologically diverse group of leading scholars of constitutional law and immigration. Our brief explains that the Fourteenth Amendment means what it says: everyone who is born in the United States and subject to its authority is entitled to the privileges of citizenship at birth. Our brief makes three principal points.

First, the Fourteenth Amendment’s text guarantees birthright citizenship to children born to noncitizens, no matter their immigration status. The Citizenship Clause embodies the jus soli rule of citizenship under which citizenship is acquired by right of the soil rather than by bloodline.  By extending citizenship to persons “subject to the jurisdiction” of the United States, the Clause sweeps broadly to include anyone who is “subject to the authority of the U.S. government.” Dictionaries and international legal practice at the time of the Fourteenth Amendment’s drafting and ratification confirm that virtually everyone born within the United States was considered subject to its jurisdiction. The only exceptions were exceedingly rare: children of foreign rulers themselves, foreign diplomats, and foreign military forces, as well as members of Native American tribes. And as the Amendment’s history makes clear, the Framers were aware that the Clause would apply to the children of noncitizens who were in the country unlawfully or who did not intend to stay in the country permanently.

Second, longstanding precedent confirms that the Fourteenth Amendment establishes birthright citizenship for children of noncitizens, irrespective of their parents’ immigration status. Soon after the Amendment’s ratification, courts, including the Supreme Court, recognized that it guaranteed birthright citizenship to the children of noncitizens. In the 1898 United States v. Wong Kim Ark decision, the Supreme Court held that the Fourteenth Amendment “reaffirmed in the most explicit and comprehensive terms” the “fundamental principle of citizenship by birth within the dominion,” which included children born to noncitizen parents. The Court exhaustively surveyed the common law origins of birthright citizenship, the history of the Citizenship Clause, and contemporary interpretations of the Clause’s scope, and concluded “the effect of birth [is] declared by the [C]onstitution to constitute a sufficient and complete right to citizenship.” In the decades since Wong Kim Ark, the Supreme Court has repeatedly affirmed and relied upon its holding.

Finally, as the text and history of the Fourteenth Amendment make clear, Trump’s order is unconstitutional. The government’s arguments that “subject to the jurisdiction” means “political jurisdiction” and that “political jurisdiction” only includes “persons who owe primary allegiance” to the United States are without merit and misconstrue the relevant history. The government’s argument that the Citizenship Clause requires either “primary allegiance” or “domicile” is also entirely unsupported by text or history. Indeed, the government’s theory that those unlawfully present in this country are precluded by law from establishing domicile and “primary” allegiance to the United States is irreconcilable with one of the chief purposes of the Citizenship Clause: endowing citizenship to persons of African descent born in the United States.

The Fourteenth Amendment guarantees birthright citizenship to virtually all children born in the United States, no matter the immigration status of their parents.  The Ninth Circuit should reject the Trump Administration’s arguments and affirm the decision below and the bedrock constitutional principle of birthright citizenship.