The building of the blockchain is predicted to harken the end of the contemporary sovereign order. Some go further to claim that as a powerful decentering technology, blockchain contests the continued functioning of world capitalism. Are such claims merited? In this paper we consider sovereignty and blockchain technology theoretically, posing possible futures for sovereignty in a blockchain world. These possibilities include various forms of individual, popular, technological, corporate, and techno-totalitarian state sovereignty. We identify seven structural tendencies of blockchain technology and give examples as to how these have manifested in the construction of new forms of sovereignty. We conclude that the future of sovereignty in a blockchain world will be articulated in the conjuncture of social struggle and technological agency and we call for a stronger alliance between technologists and democrats.