This article explains the impact of substate nationalism on the political dynamic surrounding ethnic kin migration through a case study of Sri Lankan Tamil refugees in the southern Indian State of Tamil Nadu. Examples drawn from the migration studies literature identify ethnic kinship between refugees and host as an indicator of favorable reception and assistance. While this expectation is borne out to an extent in the Tamil Nadu case, it is tempered by a period of hostility following the 1991 assassination of former Indian Prime Minister Rajiv Gandhi by an LTTE suicide bomber, when the refugees were figured as a disruptive and dangerous presence by Tamil Nadu's political elites. A version of the “triadic nexus“ model of kin state relations, reconfigured to accommodate the larger political unit within which the substate nationalism is incorporated, is proposed as a framework of analysis for these events. This can better account for Tamil Nadu's substate ethnonationalist elite's movement between expressions of coethnic solidarity with the refugees and the more hostile, security-focused response post-assassination.