After Dobbs, part of the public conversation regarding the future of abortion in the United States was about the issue of fetal personhood. The ultimate goal for some, the ultimate fear for others. This paper tells the story of how fetal personhood was won—and then lost—by Argentina’s anti abortion movement in the 1990s. It shows how a certain constitutional narrative, born within civil society, managed to persuade public officials to elicit constitutional change. It also shows how that change left open room for contestation and how—eventually—the bastion implied in the successful constitutional argument fell, under the weight of a counter-narrative. The paper makes a contribution to the literature that studies the relationship between law and politics in the context of extended and pervasive disagreement.