We investigate the effect of populism in countries experiencing severe economic inequality. We posit that left populist parties use a mix of strong redistribution policies, which tackle the roots of political dissatisfaction, and anti-elite rhetoric, which increases credibility in maintaining the electoral pledges, to build electoral support. In turn, this policy and rhetoric innovation leads to an increase in trust in institutions among left populist voters, especially when their party is in power. We test our argument in Latin America, using a repeated cross-section individual-level dataset (1995-2020) and an original survey experiment. We find strong evidence that left populist parties elevate political trust among their voters and that this positive effect is driven by pledges to implement generous redistributive policies. Trust does not increase among voters of other party’s families, including right populist parties. We also find that the use of populist rhetoric increases voters’ confidence in the actual implementation of social spending and poverty reduction programs when left populist parties are the incumbent.