The traditional narrative of Europe's first wave of democratization is that elites extended the franchise in response to revolutionary threats and reformed majoritarian electoral systems to limit rising working-class parties. This stylized account does not fit early twentieth-century South America, where democratization was driven by internal competition within incumbent parties, without strong working-class parties to contain. I study Argentina's 1912 electoral reform that introduced elements of democracy (secret and compulsory voting) and simultaneously changed the electoral system from multi-member plurality to the limited vote. To study the motivations behind the electoral system change component of the reform package, I analyze expert surveys, legislative debates, and a 1911 public opinion poll. Granting representation to political minorities was regarded not as an electoral containment strategy to benefit incumbents, but a progressive measure to make opposition parties more competitive. An analysis of roll-call votes shows that legislators who supported the reform were those expecting to not be adversely affected.