The Supreme Court on Monday dismissed a challenge by a Mexican-born man to a citizenship law that treats men and women differently.

The court split 4-4 in the case of Ruben Flores-Villar, an outcome that upholds his criminal conviction on immigration charges. The tie vote resolves Flores-Villar's case, but sets no national precedent. Justice Elena Kagan did not take part because she worked on the case when she was Solicitor General.

Flores-Villar, 36, was born in Tijuana to an American father and Mexican mother. If his parents' nationalities were reversed, Flores-Villar would be a citizen. American mothers need only to have lived in the United States continuously for a year before the birth of a child. It's longer for a citizen father.

When the court heard the case in November, the justices expressed some sympathy for Flores-Villar's plight, but noted that the court has never taken the step of granting citizenship — the only outcome that would have allowed him to prevail on his appeal of the immigration charges.