Should political elections be implemented using blockchain technology? Blockchain evangelists have argued that it should. This article sheds light on the potential of blockchain voting procedures and the legal constraints that need to be accommodated. I first identify the upsides of the distributed ledger technology and the normative principles guiding electronic voting systems. Specifically, I elucidate some of the major normative constraints for blockchain voting systems in a transatlantic comparison of U.S. and German constitutional law. I then discuss the technological, economic and normative limitations of blockchain voting procedures. On the one hand, these limitations result from the rules and incentives set by different consensus mechanisms. On the other hand, it is far from clear whether blockchain technology provides sufficient safeguards to ensure identity verification, the secrecy of ballots, and a verification that ballots are cast as intended, recorded as cast, and counted as recorded. Building on principles from constitutional law, I contend that blockchain technology may not provide sufficient safeguards to satisfy the requirements of democratic voting procedures, at least not in the near future.