Infrastructures are technical-social assemblages infused in politics and power relations. They spur public action, prompting increased scholarly reference to the practices of infrastructural publics. This article explores the normative and conceptual meanings of infrastructures, publics, and infrastructural publics. It distills from political theory traditions of Hannah Arendt, Jürgen Habermas, and Nancy Fraser a normative ideal of publics composed of the persons subject to a particular configuration of power relations that may significantly affect their autonomy. Autonomy can be seriously affected not only by existing or planned infrastructures, with their existing or anticipating users and workers and objectors, but also by the lack of an infra-structure or by the terms of infrastructural exclusions, rationings, channelings, and fiscal impositions. Legal-institutional mechanisms provide some of the means for infrastructural publics to act and be heard, and for conflicts between or within different publics to be addressed, operationalizing legal ideas of publicness. These mechanisms are often underprovided or misaligned with infrastructure. One reason is the murkiness and insecurity of relations of infrastructural publics to legal publics constituted or framed as such by institutions and instruments of law and governance. We argue that thoughtful integration of infrastructural and legal scaling and design, accompanied by a normative aspiration to publicness, may have beneficial effects.