This book examines how political discourse on immigration is constructed across Italian social media, focusing on the ways “otherness” is reshaped within digital platforms. Drawing on Social-Media Critical Discourse Studies, it introduces the concept of alternative otherness to explain how migrants are symbolically repositioned in a polarized and mediatized communicative environment. The book is structured in three main parts. The first reconstructs and connects key socio-technical processes that shape the conditions under which political discourse on immigration emerges. The second part outlines the theoretical and methodological framework, grounded in the critical tradition of Critical Discourse Studies and its extension to social media environments. The third part presents four empirical case studies examining emblematic episodes related to immigration in the Italian context between 2017 and 2025, showing how political actors construct and circulate recurring discursive patterns that progressively shift attention away from migrants themselves toward new forms of antagonism.