In this article I argue for a kinship anthropology of politics, understood as a focus on the day to day imbrications of kinship and politics in a given political space, and the implications of that for the construction of political subjects. I describe kinship within shop-floor level trade union delegations of state employees in Argentina in three different ways: first, languages of kinship mobilised to describe political allegiance and dispositions, especially inheritance; second, family connections in recruitment and activism; and third, practices of kinning as relatedness. The combination of these three kinship modes creates the union as kin group, and enables them to act on the world politically in order to transform it.