The U.S. Supreme Court case Sessions, Attorney General v. Morales-Santana (2016) revolved around the issue of citizenship laws and gender discrimination. Luis Ramon Morales-Santana was born in 1962 in the Dominican Republic to an unwed American father and a Dominican mother. His father had lived in Puerto Rico until 20 days before his 19th birthday, which is just short of the five years required by law for a parent to pass on U.S citizenship to their child if born abroad out-of-wedlock and not subsequently legitimated by marriage between parents. Morales-Santana claimed that this requirement violated equal protection as it discriminated based on gender since mothers only needed one year of physical presence to confer citizenship onto their children under similar circumstances. The court ruled in favor of Morales-Santana stating that such disparate treatment indeed violated equal protection principles but did not grant him relief because instead of extending benefits given to unwed mothers, they leveled up requirements for both genders making them equally burdensome.

In the dissenting opinion for Sessions, Attorney General v. Morales-Santana (2016), Justice Thomas, joined by Justice Alito, argued that the court overstepped its boundaries in attempting to provide a remedy for an equal protection violation. They contended that it was not within the Court's power to extend benefits of citizenship laws or rewrite them but rather Congress should be responsible for such changes. The dissenters also disagreed with the majority’s interpretation of gender discrimination under equal protection clause and believed there were plausible policy reasons behind different residency requirements based on whether unwed citizen mothers or fathers were involved. Furthermore, they expressed concern about potential implications this ruling could have on immigration law and other statutes where differential treatment exists between mothers and fathers.