Democratic societies such as the United Kingdom have come to fail their young citizens, often sacrificing their interests in a political process that gives much greater weight to the preferences and interests of older citizens. Against this background of intergenerational injustice, this article presents the case for a shift in the political system in the direction of radical democratic inclusion of younger citizens, through reducing the voting age to 12. This change in the voting age can be justified directly, with reference to the status, interests, and capacities of younger citizens, and it can also be justified as a remedy to existing forms of intergenerational injustice. This change in the voting age would require a parallel transformation in the role of secondary schools as part of the ‘critical infrastructure' of a democratic society, which would be part of a broader shift towards a more genuinely democratic political culture. The proposal is defended against less radical alternatives (such as votes at 16) and more radical alternatives (such as votes for younger children). The article concludes with some reflections on democracy and intergenerational justice in light of the Covid pandemic and the climate emergency.