This paper seeks to understand the socio-political dimension of the political changes in Assam vis-a-vis “regionalism” and its contestations. The Changing contours of regionalism in Assam reflect its distinct character marked by the simultaneous articulation of regional, sub-regional and national identity in a complex socio-ethnic and historical context. The recent political trajectory of Assam bears testimony to the dual challenges facing the forces of regionalism; the presence of sub-regional ethnic identity articulation and the appropriation of regional space and issues by the national parties. Further, the shifting allegiance of ethnic identity-based parties to the national parties is critical to understand the dynamics of regionalism in Assam. Socio-political developments subsequent to the rise of BJP post-2014 provide an interesting landscape to comprehend the complexities inherent in understanding regionalism in contemporary Assam. On a contextual note, the paper also locates the question of regionalism in the ongoing debates of NRC and CAA.