Even if populism is not simply an illiberal ideology, it is bad for democracy. Because populists are not constrained by power-seeking party elites, they are more likely, on average, to erode civil liberties and judicial and legislative constraints on their authority. At the extreme, populists so erode these constraints that they cross the threshold into authoritarianism. The best defense against this democratic rollback is not to be found in policy alone. Rather, institutional changes are needed that incentivize power-seeking politicians to create and sustain bureaucratic parties. The conditions that produced the mass membership parties of the twentieth century have essentially passed. But a new generation of programmatic political organizations could sustain democracy well into the future, taking advantage of new tools to map how we live and work, integrating people across space, and forging new civil and political spaces.