This article explores the reasons why the most important anti-corruption campaign in twentieth-century Venezuela failed to win sustained support. Employing a constructivist approach to historical actors’ understandings of corruption, it analyses the debates that erupted when the Acción Democrática (Democratic Action, AD) party prosecuted 167 former officials for illicit enrichment. The ensuing debate demonstrates that AD and its opponents disagreed over the proper boundaries between the public and private spheres in a modern state. AD sought to punish officials who used public office for private gain, but critiques of the trials effectively countered AD and contributed to its overthrow in 1948.