This paper seeks to make a moral argument for citizens’ need to create networks of solidarity with non-citizens. Instead of concentrating on the political mobilization of migrants themselves, it thus highlights the theoretical grounds on which notions of responsibility and solidarity can be extended to ‘non-members’ within established political communities. This goes against prevalent modes of argumentation in modern political thought, where solidarity and responsibility are mostly defined in terms of shared social or political identities. To establish this alternative line of argumentation, the paper draws on the works of Emmanuel Levinas, Judith Butler and Jacques Derrida.