More and more, political life in Latin America is playing out on social media. What are the implications for democracy? Recent elections in Argentina, Brazil, El Salvador, and Mexico show that social media can help to elevate political outsiders and spread sophisticated misinformation. Survey data show that while social-media users are more supportive than others of democratic principles, they have more negative views of their political systems. While there have been important innovations in combating misinformation, policy makers must also focus on the underlying conditions that are the fodder for social media’s ill effects: political polarization and deepening public distrust of democratic institutions.