The outgoing U.K. Parliament tried to block a “hard” interpretation of the Brexit referendum outcome, and only authorized an early election when that seemed in place. But under the Westminster system a Parliament cannot bind its successor, and in December 2019 a purged hardline Conservative party won a decisive majority. There are wider lessons for contemporary democracies. Representative governments can add referendums to their existing electoral mechanisms, but that requires great care and foresight. National sovereignty can be a powerful mobilizer of opinion, but can jeopardize territorial unity. Although disengaging from external entanglements can seem liberating, it can also prove polarizing. Losers in a democratic contest must accept the verdict of the polls, but such defeats can still be bitterly resented and can cause lasting damage to political harmony.