Abstract: This essay argues that invoking the concept of the “constituent power” clarifies some persistent puzzles about the constitutional and legal status of purportedly unconstitutional constitutional amendments. It argues that in some circumstances such amendments should be understood as exercises of the constituent power, effecting revolutionary transformations in a nation’s constitutional identity but—sometimes—through the forms of legality. The essay distinguishes between a purely conceptual version of the constituent power and a more sociological or real-world version, and argues that the former is superior to the latter.