- Arizona Attorney General Kris Mayes and 22 states filed a legal brief to protect birthright citizenship.
- The coalition argues that the 14th Amendment’s mandate cannot be overturned by an executive order.
- A Supreme Court decision on the Barbara v. Trump case is expected by mid-2026.
(ARIZONA) — Arizona Attorney General Kris Mayes joined attorneys general from 22 other states and the District of Columbia in filing an amicus brief backing birthright citizenship in Barbara v. Trump, arguing that President Donald Trump’s executive order cannot strip automatic citizenship from certain children born in the United States.
The coalition urged the courts to keep in place the long-standing rule that U.S.-born children are citizens under the 14th Amendment’s Citizenship Clause and the federal statute known as INA § 1401, calling the executive order inconsistent with constitutional text, Supreme Court precedent and federal law.
“The Fourteenth Amendment is crystal clear: if you are born in the United States, you are an American citizen. President Trump does not have the power to change that with the stroke of a pen,” Mayes said.
The brief frames the dispute as a nationwide question with immediate consequences for states that administer public benefits and issue documents that often depend on citizenship status, as well as for families whose children’s citizenship could hinge on how the Supreme Court reads the Citizenship Clause.
At the center of the case is Trump’s Executive Order, which the states said targets U.S.-born children of parents who are neither U.S. citizens nor lawful permanent residents by denying them automatic citizenship at birth.
Mayes and her counterparts argued that the 14th Amendment, ratified 1868, set a constitutional rule that a president cannot rewrite through an executive order, and that Congress also codified the same principle in INA § 1401.
An amicus brief, short for “friend of the court,” allows jurisdictions and other non-parties to offer legal arguments and discuss practical effects without taking over the litigation. Arizona and the other jurisdictions used the filing to press a legal interpretation and to describe what they called concrete administrative and funding harms.
The coalition said the executive order would cause disruptions across state systems because states routinely must determine eligibility for programs, issue or verify records, and coordinate with federal agencies in ways that assume a stable citizenship framework for children born in the United States.
In the brief, the states also tied the order to federal funding streams, warning that changing the rules for citizenship recognition could reduce federal support connected to programs they identified as Medicaid, CHIP, foster care, and adoption assistance.
Beyond funding, the states said they would face new administrative costs to adjust eligibility and benefits in response to new citizenship rules, describing a cascade of verification burdens and policy rewrites that would follow if automatic citizenship for affected U.S.-born children were denied.
The states anchored their legal argument in Supreme Court precedent they characterized as longstanding, contending that the executive order conflicts with the Court’s existing approach to the Citizenship Clause and therefore cannot stand.
The amicus brief also relied on federal statutory language, pointing to INA § 1401 as Congress’s statement of who is a citizen at birth and arguing that an executive order cannot override that statute.
Those arguments arrive in a case that has already generated multiple court orders keeping the executive order from taking effect while the litigation proceeds, leaving the status quo in place for now but with uncertainty hanging over families and state agencies pending Supreme Court review.
Lower courts blocked the executive order through nationwide preliminary injunctions in state-led suits, including litigation filed by Arizona, Illinois, Oregon and Washington in the Western District of Washington.
A separate class action in federal court in New Hampshire, the case known as Barbara v. Trump, won certification covering “all affected babies born on or after February 20, 2025,” a definition that the states’ brief and related filings have treated as central to who receives protection while the case remains unresolved.
Class certification matters because it allows a court to issue relief for an entire group defined by the court, rather than only for the named plaintiffs, and it can determine how broadly an order applies to families with U.S.-born children while appeals continue.
In another major step, the 9th Circuit, in July 2025, upheld recognition of citizenship for all U.S.-born babies, reinforcing the practical baseline the states want the Supreme Court to preserve.
Those interim rulings, taken together, have kept federal agencies and state systems operating on the assumption that U.S.-born children are citizens, even as the administration continues to argue for a narrower view of constitutional birthright citizenship.
The Supreme Court will hear oral arguments in Trump v. Barbara, consolidated from Barbara v. Trump, on April 1, 2026, with a decision expected by late June or early July 2026.
The administration’s position, as described in the case, contends that the 14th Amendment was limited to formerly enslaved people and their children and is not broadly applicable today, an interpretation that would narrow who qualifies for citizenship at birth.
The states urged the justices to reject that view, arguing that the Citizenship Clause sets a general rule for people born in the United States and that both constitutional and statutory text support automatic citizenship for U.S.-born children even when their parents are not citizens or lawful permanent residents.
Even with the case set for argument, the practical question for families and agencies in the months ahead remains shaped by the litigation posture and existing injunctions, which can determine whether and how the executive order could be implemented before a final judgment.
Mayes and the other attorneys general presented the states as having an institutional stake in clear, uniform citizenship rules because state programs often depend on quick, consistent determinations that do not vary by shifting federal policy.
In their filing, the coalition also emphasized historical and interpretive arguments, pointing to what they described as the ratification-era understanding of the Citizenship Clause and common-law principles that treated birth within the sovereign’s territory as a basis for citizenship.
The brief highlighted “foundlings” — abandoned babies — as a test of the administration’s approach, arguing that under the historical understanding the states described, such children were treated as citizens regardless of unknown parentage.
By invoking foundlings and common-law ideas, the states sought to show that birthright citizenship has been understood broadly in the United States and that the rule does not depend on proving the citizenship or immigration status of parents at the moment of birth.
Arizona’s coalition consisted of 23 Democratic AGs total, a political alignment the brief reflects in its criticism of the executive order and its insistence that the executive branch lacks authority to reshape the Citizenship Clause’s core meaning.
Alongside Mayes, the jurisdictions joining the amicus brief were California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon, Rhode Island, Vermont, Virginia, Washington, plus D.C.
The filing adds to a broader pattern of multistate litigation over immigration-related policies, where states increasingly appear on opposing sides of federal action and use nationwide injunctions and consolidated appeals to press legal challenges to executive authority.
In this case, the states backing birthright citizenship cast the executive order as an attempt to achieve through presidential action what they argued cannot be done without constitutional change and, at minimum, without Congress.
The brief’s focus on Medicaid, CHIP, foster care, and adoption assistance underscored that the states view the dispute not only as a constitutional fight but also as a question with immediate effects on the systems states run and the budgets they must balance.
The administrative burdens the coalition described also reflect the practical mechanics of citizenship recognition, as eligibility decisions, documentation, and intergovernmental coordination can become more complex when citizenship rules shift or vary by category.
The Supreme Court’s decision, expected by late June or early July 2026, will come after months in which lower-court rulings have maintained birthright citizenship recognition for U.S.-born babies while the justices consider whether the administration can narrow the Citizenship Clause.
For Mayes and the other attorneys general, the amicus brief in Barbara v. Trump is intended to keep birthright citizenship intact as the case moves to the Supreme Court’s hearing, with the coalition’s central message encapsulated in Mayes’s statement that, “The Fourteenth Amendment is crystal clear: if you are born in the United States, you are an American citizen.”
