Lawyer Alex Ali Mendez Diaz represented three same-sex couples from the Mexican state of Oaxaca whom local authorities denied marriage licenses. (Photo courtesy of Alex Ali Mendez Diaz)

The Mexican Supreme Court on Wednesday unanimously struck down a law in the southern state of Oaxaca that defined marriage as between a man and a woman.

Three couples — Lizeth Citlalli Martínez Hernandez and María Monserrat Ordóñez Narváez, Jesús Reyes Álvarez and Guillermo Emmanuel Martínez Pimental and Karina Mendieta Pérez and Gabriela Castellanos Mota — tried to apply for marriage licenses in Oaxaca, but local authorities denied their applications.

Lawyer Alex Alí Méndez Díaz filed lawsuits on behalf of two of the couples in Aug. 2011 and a third in January who sought legal recourse, known as an “amparo” in the Mexican judicial system, that would ensure local authorities would protect their constitutional rights. Geraldina González de la Vega, a lawyer who advised Méndez, noted to the Washington Blade this “remedy can be used against laws or acts of authority” in Mexico.

A Oaxacan court in April ruled in favor of Martínez and Ordóñez, but against Reyes and Martínez and Mendieta and Castellanos. An appellate judge in August cited the Mexican constitution that bans anti-gay discrimination in his ruling that ordered Oaxacan authorities to allow same-sex marriages.

The state’s governor and Congress petitioned the Mexican Supreme Court to review the case — Méndez also asked the tribunal to determine the criteria under which the Oaxacan marriage law should be understood.

“The court did not declare the unconstitutionality of the law, but the effect of its application is that the justices said that one would have to understand marriage is a contract celebrated between two people without any reference to the sex of those who enter into it,” Méndez told the Washington Blade during an interview from Mexico City hours after the justices issued their decision.

Same-sex couples have been able to legally marry in the Mexican capital since 2010, and the Mexican Supreme Court has ruled other states must recognize same-sex marriages legally performed in Mexico City. Same-sex couples have also married in Quintana Roo, which includes the resort city of Cancún on the Yucután Peninsula.

The state of Coahuila offers property and inheritance rights and other limited legal protections to same-sex couples.

The latest Mexican Supreme Court decision only applies to Oaxaca, but advocates maintain these cases will open the doors to same-sex marriages across the country.

González noted the court needs to issue five rulings before the “amparo” will “have general effects” throughout the country.

“We already have three,” she said.

“These cases set a precedent that can be invoked in any other state in Mexico,” Méndez added. “While it is not obligatory for those who must resolve these new cases, there is a high possibility that the result will be the same as what we have obtained in Oaxaca.”

Enrique Torre Molina, an LGBT activist and blogger in Mexico City, agreed.

“It’s not going to be long before same-sex marriage is a reality in the whole country,” he told the Blade on Wednesday. “It’s a matter of same-sex couples who have been thinking about getting married and haven’t done it either because they’re not in Mexico City and traveling is not an option or because they were going to get no for an answer. It’s just a matter of time of trying it out as these couples in Oaxaca [did] and sort of contribute to this history.”

The Mexican Supreme Court issued its ruling hours after a Colombian Senate committee approved a measure that would legalize same-sex marriage. Senators in the South American country are expected to debate the bill on Tuesday.

Same-sex couples have been able to legally marry in Argentina since 2010. Neighboring Uruguay allow civil unions for gays and lesbians, but the country’s lawmakers are expected to debate a same-sex marriage measure on Tuesday.

The Inter-American Court of Human Rights in February ruled in favor of lesbian Chilean Judge Karen Atala who lost custody of her three daughters to her ex-husband in 2005 because of her sexual orientation. Three gay Chilean couples who had been denied marriage licenses filed a lawsuit with the tribunal in September after the country’s Supreme Court ruled against them.

The Mexican Supreme Court cited the Atala case in its decision.

“Our country has already been sanctioned on many occasions by the IACHR,” Méndez said. “Our country, being part of this Inter-American system, will have to follow this trend in regard to protecting the human rights of the LGBT community.”

J. Lester Feder, a former Politico reporter who has covered the same-sex marriage throughout Latin America for four months for his blog AfterMarriage.org, noted to the Blade from Oaxaca that courts throughout the region often look to those in other countries in reaching their own decisions. He said the Atala case is one of the legal precedents the Oaxacan couples used in their successful lawsuits.

Justice José Ramón Cossío told CNN en Español he expects the same-sex marriage could become a reality throughout the country within a few months.

“The three cases are effective with respect to the state of Oaxaca,” he said. “By the position that we have on the Supreme Court as the country’s highest tribunal, it is foreseeable that if other people from other federal entities challenged a code that had a similar condition, the court would reiterate its criteria and within the next few months will guarantee the juris prudence that will become mandatory.”

Feder agreed.

“It means that it’s very likely universal marriage rights are going to be available in Mexico well before the United States,” he said. “International human rights law in the Americas is [increasingly interpreting] marriage rights as human rights, but the United States legal system doesn’t internalize international norms. We’re not participating in that trend.”