Social media platforms, once hailed as potential champions of dialogue, have evolved into commodified spaces in which their business models incentivize hate speech, misinformation, polarization, and the political fragmentation of society, benefiting corporate and political elites while eroding democracy. The existing market and technological conceptualizations of social media platforms offer only partial analysis of and solutions to these issues. This paper advances a political perspective grounded in deliberative democracy, arguing that social media companies are political actors responsible for maintaining a well-functioning public sphere. We argue that transforming social media platforms into true facilitators of democratic discourse requires enhancing their deliberative capacity. Beyond the capacities of the public sphere suggested by the market and technology perspectives (1) transparency and accountability and (2) openness and inclusiveness, we propose that fostering deliberative capacity also requires (3) conduciveness to argumentation and (4) consequentiality. We thus contribute to understanding how management theories can explain and address current threats to democracy.