Professor Santiago Legarre is a Professor of Law at Universidad Católica Argentina and a Visiting Professor at Strathmore Law School (Kenya) and Notre Dame Law School (Indiana). His talk will focus on comparative constitutional law, taking the US legal practice as an example. The presence of comparative analysis is considered both in the academic arena and in the case law of the US Supreme Court. The conclusion of the talk is that for comparative constitutional law to be valid its role ought to be restricted by several constraints. Crucially, it ought to be distinguished from international law, to avoid manipulation of foreign sources and the substitution of domestic law by judges and litigators' preferences for foreign solutions. Finally, the talk provides an Argentine example of the misuse of comparative constitutionalism.