This dissertation aims to research the impacts generated by the communicative structures of digital platforms in the discursive level of public sphere and in the practices of informal deliberation, analysing social media and their algorithm based system of information that operates through massive data collection and fragmented arenas, mechanisms that have produced significant distortions in public communication, especially in the political sphere. And also to investigate on the current electoral context, the proceeding of political campaigns and social movements, propaganda tools and companies that, for promoting mass disinformation, caused a retraction in the public debate, intensifying political polarisation and radicalism, reducing the effectiveness of the public sphere.