At present, Mexico City is the only jurisdiction that conduct same sex marriages. In recent years several states have attempted to introduce similar legislation, but have failed. I did see a statement last week that "several" stated currently have marriage legislation under consideration, but I have not been able to find corroboration or details. I would guess that this ruling by the court, which comes so quickly after the legislation in Argentina, will at least increase the political pressure on other states to follow.
(Last week the court rejected an attempt to have Mexico City's marriage law declared unconstitutional. Yesterday's decision was the second in a series of three related questions the court is considering. They have still to rule on a matter of gay adoption.)
>MEXICO CITY — The Mexican Supreme Court ruled Tuesday that each of the country’s 31 states must recognize same-sex marriagesregistered in Mexico City, potentially giving gay and lesbian couples full matrimonial rights nationwide.
The court had already ruled this month that Mexico City’s same-sex marriage law, which took effect in March and has resulted in hundreds of same-sex marriages, was constitutional.
But on Tuesday, the court went a step further, ruling 9 to 2 against a complaint from the attorney general’s office, which had said that other jurisdictions should not be required to honor marriages that were performed in Mexico City.
While the court made it clear that state governments were not obligated to enact same-sex marriage laws of their own, it did require them to recognize the legality of such marriages performed in Mexico City.