Resum
The article analyzes a recent string of cases decided by the Mexican Supreme Court regarding sexual and reproductive rights on issues such as abortion, gay marriage and adoption by same-sex couples, and transgender identity. The purpose of this inquiry is two-fold. At one level, it seeks to sort out what the Court has in fact said and refrained from saying about the fundamental rights involved –sexual liberty and reproductive liberty– and contrasting the disparate articulation of the Court’s constitutional doctrine regarding each. At a second level, it seeks to illustrate, through the analysis of a family of cases, how the Court is struggling to define its newfound role as the instance in charge of substantively interpreting the Constitution and, specifically, the fundamental rights there contained. It proposes that the disparate articulation of the rights of sexual liberty and reproductive liberty reflect a deeper tension within the Court: whether to continue in a formalistic tradition that understands the Constitution as a set of rules to be applied, or to assume a new role as the ultimate interpreter of the Constitution.