Crowdsourcing legislation gives ordinary citizens, rather than political and bureaucratic elites, the chance to cooperate to come up with innovative new policies. By increasing popular involvement, representative democracies hope to restock dwindling reserves of political legitimacy. However, it is still not clear how involvement in legislative decision making affects the attitudes of the participants. It is therefore of central concern to establish whether crowdsourcing can actually help restore political legitimacy by creating more positive attitudes toward the political system. This article contributes to this research agenda by examining the developments in attitudes among the users on the Finnish website Avoin Ministeriö (“Open Ministry”) which orchestrates crowdsourcing of legislation by providing online tools for deliberating ideas for citizens' initiatives. The developments in attitudes are investigated with a two-stage survey of 421 respondents who answered questions concerning political and social attitudes, as well as political activities performed. The results suggest that while crowdsourcing legislation has so far not affected political legitimacy in a positive manner, it has the potential to do so.