This paper explores the relationship between social media and political rhetoric. Social media platforms are frequently discussed in relation to ‘post-truth’ politics, but it is less clear exactly what their role is in these developments. Specifically, this paper focuses on Twitter as a case, exploring the kinds of rhetoric encouraged or discouraged on this platform. To do this, I will draw on work from infrastructure studies, an area of Science and Technology Studies; and in particular, on Ford and Wajcman’s analysis of the relationships between infrastructure, knowledge claims and politics on Wikipedia. This theoretical analysis will be supplemented with evidence from previous studies and in the public domain, to illustrate the points made. This analysis echoes wider doubts about the credibility of technologically deterministic accounts of technology’s relationship with society, but suggests however that while Twitter may not be the cause of shifts in public discourse, it is implicated in them, in that it both creates new norms for discourse and enables new forms of power and inequality to operate.