On May 3 the U.S. Supreme Court issued a unanimous opinion authored by Justice Kennedy in the case of INS v. Aguirre-Aguirre, reversing the Ninth Circuit’s ruling that the Board of Immigration Appeals (BIA) applied an improper standard in determining that Aguirre-Aguirre had committed a "serious nonpolitical crime" before entry into the U.S.

Aguirre-Aguirre was a student activist in his native Guatemala, who, while protesting the government’s treatment of students, in particular the need for student transportation, burned busses, assaulted passengers, and destroyed private property. The BIA determined that these were serious nonpolitical crimes making Aguirre-Aguirre ineligible for asylum even if he did prove that persecution was likely to occur if he was returned to Guatemala. The Ninth Circuit reversed, primarily on the ground that the BIA failed to take into consideration the political necessity and effectiveness of his actions, as well as whether the acts were grossly out of proportion with the goal he sought. The Ninth Circuit also ruled that the BIA erred in weighing the likelihood of persecution against the nature of the crimes.

As an initial point, the Supreme Court noted that the Illegal Immigration Reform and Immigrant Responsibility Act did not apply because the BIA rendered its final decision in May 1996. Under IIRAIRA, Aguirre-Aguirre would not be eligible for asylum at all. Prior to IIRAIRA, a grant of asylum was discretionary whatever the circumstances of the case; under IIRAIRA, asylum may not be granted if "there are serious reasons for believing that the alien has committed a serious nonpolitical crime outside the United States."

The primary basis for the reversal of the Ninth Circuit was its failure to give the appropriate level of deference to the BIA’s decision. Because the BIA’s decision rested on its interpretation of the law it administers, the Ninth Circuit should have applied the standard of whether the agency’s decision was "based on a permissible construction of the statute." In each of the Ninth Circuit’s bases for reversing the BIA, it erred in failing to give the Board the appropriate level of deference.

According to the Supreme Court, the most serious error of the Ninth Circuit was its requirement that the BIA balance the nature of the criminal acts with the risk of persecution if returned. The Supreme Court wrote "As a matter of plain language, it is not obvious that an already-completed crime is somehow rendered less serious by considering the further circumstance that the alien may be subject to persecution if returned to his home country." While the United Nations Handbook on Determining Refugee Status does contain language about striking a balance between the crime committed and the persecution faced, the Handbook is not binding on either the Attorney General, the BIA, or the courts of the U.S.

The Ninth Circuit also erred, according to the Supreme Court, in finding the BIA must consider whether the crimes committed were atrocious or grossly out of proportion with the political objective. The Supreme Court found the BIA had in fact made this very determination.