Tuan Anh Nguyen v. Immigration & Naturalization Service
The Supreme Court upheld a federal law that imposes extra requirements on unmarried American fathers, but not unmarried American mothers, before their children born abroad can become U.S. citizens.
The Court found the different treatment justified by real biological differences in how parenthood is established at birth, allowing the law to stand even though it explicitly treats men and women differently.
“The difference between men and women in relation to the birth process is a real one, and the principle of equal protection does not forbid Congress to address the problem at hand in a manner specific to each gender.”
The majority's closing explanation for why treating unmarried fathers and mothers differently does not violate equal protection.
How it got here: An immigration judge and the Board of Immigration Appeals ruled Nguyen was not a citizen; the Fifth Circuit affirmed, and the Supreme Court took the case to resolve a circuit split.
The Case in Depth
What happened
Tuan Anh Nguyen was born in Vietnam to an American father, Joseph Boulais, and a Vietnamese mother who were never married. Nguyen came to the U.S. as a child and was raised by his father in Texas. After Nguyen pleaded guilty to sexual assault as an adult, the government sought to deport him as a noncitizen, and he argued he was actually a U.S. citizen through his father.
The question before the Court
Can Congress require an unmarried American father — but not an unmarried American mother — to take extra legal steps before their foreign-born child can become a U.S. citizen?
The Court's answer
Yes — the Court ruled that Congress can impose extra requirements on unmarried American fathers, but not unmarried American mothers, when it comes to passing citizenship to a child born abroad out of wedlock. The law survives the tough legal test for sex-based laws because it addresses a real biological difference: a mother's link to her child is obvious from giving birth, while a father might never even know of the child's existence or be present at birth.
The Court found two important goals behind the law — confirming a real biological connection and ensuring some realistic chance for father and child to form a relationship — and concluded that requiring fathers to legitimate the child, sign a sworn statement of paternity, or get a court order before the child turns 18 reasonably serves those goals without being an unfair stereotype.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
The ruling means citizen fathers of children born abroad out of wedlock must take formal steps — like legitimating the child, signing a sworn statement, or getting a court order — before the child turns 18, or the child cannot claim citizenship through the father. Citizen mothers face no such extra requirement, a distinction that will keep shaping who can and cannot claim American citizenship by birth.
What changes now
The ruling is final on the merits: the Fifth Circuit's decision rejecting Nguyen's citizenship claim stands, and he remains subject to deportation based on his criminal convictions. The decision resolves a split among federal appeals courts over the statute's constitutionality, meaning the law's different treatment of unmarried citizen fathers and mothers will continue to apply nationwide unless Congress changes it.
What this does not decide
The Court did not decide whether a lesser standard of review might apply because the law also involves Congress's immigration and naturalization powers; it assumed the stricter gender-discrimination standard applied and found the law valid even under that tougher test. It also did not resolve remedy questions like severability, since it found no constitutional violation to begin with.
Concurrences and dissents
Concurrence — Justice Scalia
Justice Scalia reiterated his view from an earlier case that the Court has no power to grant citizenship as a remedy even if the statute were unconstitutional, since only Congress can set citizenship rules. Because a majority of the Court proceeded on the assumption that such a remedy is available, he reached the merits and agreed the law survives equal protection scrutiny.
Dissent — Justice O'Connor
“I would reverse the judgment of the Court of Appeals.”O'Connor's bottom-line conclusion that the law's gender distinction fails equal protection scrutiny.
Justice O'Connor argued the majority failed to apply real heightened scrutiny, instead hypothesizing governmental interests not actually shown to be Congress's true purposes and ignoring available sex-neutral alternatives that would serve the same goals. She contended the law rests on an outdated stereotype that mothers, not fathers, are the ones likely to bond with nonmarital children, and would have struck down the provision and severed it from the statute.
How the Court got there
The legal reasoning, step by step
- The Court applied heightened scrutiny for sex-based classifications, a test requiring the government to show the law serves an important objective and that its distinctions between men and women are substantially related to achieving that objective.
- The Court identified two important governmental interests: first, making sure a real biological link between father and child exists, since a mother's link to a child is obvious from giving birth but a father's is not; and second, ensuring the father and child have a real opportunity to develop an actual relationship, since a father need not even be present at or know about the birth.
- The Court reasoned that because mothers are necessarily present at birth while fathers may never be, treating the two differently reflects a genuine biological difference rather than an unfair stereotype about men and women.
- The Court concluded that requiring citizen fathers to take one of three modest steps — legitimating the child, signing a sworn acknowledgment of paternity, or obtaining a court order of paternity — before the child turns 18 is a reasonably tailored way to serve both interests without imposing a heavy burden.
- Because the law's requirements substantially relate to these two important interests, the Court held the gender-based distinction survives heightened scrutiny and does not violate the Fifth Amendment's equal protection guarantee.