Why has protest participation seemingly exploded across much of Latin America in recent years? How do individual- and country-level characteristics interact to explain the rise of contentious politics in countries like Argentina, Brazil, and Venezuela? I contend that the recent wave of protests in Latin America is the result of trends in community engagement and institutional development across the region’s young democracies. Specifically, I argue that low-quality institutions in democratic regimes push an increasingly large number of civically active Latin Americans toward more radical modes of political participation, as governments’ abilities to deliver on citizens’ expectations fail to match the capacity for mobilization of active democrats. Drawing on cross-national surveys of Latin America, I test this argument, finding that an interactive relationship between community engagement and ineffective political institutions helps explain the recent spike in protest activity in certain cases and the vast differences in protest participation observed throughout the region.