## Facts

- Tuan Anh Nguyen was born in Vietnam in 1969, out of wedlock, to a Vietnamese mother and a U.S.-citizen father, Joseph Boulais.
- Nguyen entered the United States as a lawful permanent resident at age six and was raised by Boulais in Texas.
- At age 22, Nguyen pleaded guilty in Texas to two counts of sexual assault on a child, making him removable as an aggravated felon if he was not a U.S. citizen.
- In removal proceedings, Nguyen claimed U.S. citizenship through Boulais.
- Under 8 U.S.C. § 1409(a), for a child born abroad and out of wedlock to a citizen father and noncitizen mother, citizenship required certain acts (e.g., legitimation, sworn acknowledgment, or court adjudication of paternity with support commitment) to occur before the child turned 18.
- Boulais obtained a state-court parentage order while Nguyen’s administrative appeal was pending, but it was not obtained before Nguyen’s eighteenth birthday.
- The immigration authorities rejected Nguyen’s citizenship claim, and a federal appellate court affirmed, upholding § 1409(a) against an equal-protection challenge.

## Issues

1. Whether 8 U.S.C. § 1409(a)’s sex-based distinction—imposing additional prerequisites for citizenship through an unwed citizen father but not through an unwed citizen mother—violates the equal-protection component of the Fifth Amendment’s Due Process Clause.

## Decision

- The Supreme Court affirmed the judgment against Nguyen.
- The Court held that § 1409(a)’s different treatment of unwed citizen fathers and unwed citizen mothers survives intermediate scrutiny for sex-based classifications.
- The Court reasoned that the scheme serves important governmental objectives and that the means selected are substantially related to achieving those objectives.
- Justice Scalia, joined by Justice Thomas, concurred in the judgment on the view that setting citizenship conditions is committed to Congress, not the courts.
- Justice O’Connor, joined by Justices Souter, Ginsburg, and Breyer, dissented, arguing the statute was not adequately justified under heightened scrutiny and that gender-neutral alternatives were available.

## Legal Principles

- Federal sex-based classifications are constitutional if they serve important governmental objectives and are substantially related to achieving those objectives.
- In citizenship-at-birth rules for children born abroad and out of wedlock, Congress may account for biological and practical differences at birth between maternity (typically verifiable from birth) and paternity (often requiring additional proof).
- Congress may require additional formal steps from unwed citizen fathers to (1) establish a biological parent-child relationship and (2) ensure a meaningful connection between the child and the United States through the citizen parent.
- In the immigration and naturalization context, courts apply intermediate scrutiny while giving Congress substantial deference in structuring citizenship requirements, so long as the classification meets the governing equal-protection standard.

## Conclusion

The Court upheld 8 U.S.C. § 1409(a), concluding that its stricter requirements for citizenship through an unwed citizen father are justified by important interests in proving paternity and securing a real connection to the United States, and therefore do not violate Fifth Amendment equal protection.


Nguyen v. Immigr. & Naturalization Serv., 533 U.S. 53 (2001)