An influential analysis by Przeworski and Limongi (1997) argued that a pro-democratic culture may help existing democracies survive, but political culture does not contribute to the process of democratization, which is entirely done by elites. We challenge this conclusion, arguing that it neglects the very nature of democratization. For (as Human Development theory argues), democratization is a liberating process that maximizes human freedom by establishing civil and political rights. Consequently, the aspect of political culture that is most relevant to democratization is mass aspirations for freedom - and if a given public emphasizes these values relatively strongly, democratization is likely to occur. To test this thesis, we use data from the Values Surveys, demonstrating that a specific component of postmaterialism ('liberty aspirations') had a major impact on the extent to which societies gained or lost freedom during the Third Wave of democratization. This effect holds up in tests of Granger causality, remaining strong when we control for prior levels of freedom. No other indicator, including GDP/capita and social capital, can explain away the impact of liberty aspirations on democratization. Mass liberty aspirations play a role in democratization that has been greatly underestimated.