Hate speech poses a growing challenge for democratic societies in the platform-mediated public sphere. This article develops an interdisciplinary, conceptual–analytical framework integrating international and European human rights law, political analyses of mobilization and institutional stress, and linguistic approaches to exclusionary meaning-making. Legally, it examines the regulation of hate speech through the balance between freedom of expression and the protection of dignity and equality, with particular attention to Article 20 of the International Covenant on Civil and Political Rights and Articles 10 and 17 of the European Convention on Human Rights, as interpreted by the European Court of Human Rights. Politically, hate speech is analyzed as a strategic resource in polarized competition that facilitates boundary-making and undermines civic trust. Linguistically, the article shows why hate speech cannot be identified through lexical markers alone, highlighting indirect and coded hostility, pragmatic speech acts, and dehumanizing metaphors. It argues that effective responses require multi-instrument governance combining proportionate legal enforcement, preventive measures, and accountable platform cooperation, and advances a multidimensional account of online hostility under platform conditions.