Political commentary is a key component of news coverage in any liberal democracy. Yet theorising the role played by political commentators in a rapidly transforming media sphere – further destabilised by voters’ increasing mistrust of expertise and of political and media institutions – is rare in the social science literature. This article adopts a mixed methodological approach to argue that political commentators today perform one or more of three functions – ‘public educator’, ‘value educator’ and ‘polemicist’ – with commentators now falling into one of seven types. Given the broadening and flattening of news media dissemination and consumption – and arguably the ‘dumbing down’ and ‘shallowing out’ of news media coverage in a postmodern social media age where truth and facts are too often subordinated by rhetoric and opinion – this article argues that the role of the academic political commentator is now more critical than ever. It also argues that academic commentators must offer not only objective descriptive analysis of political events but also potentially subjective normative analysis – in effect, narrative ‘guardrails’ – to remind voters of what is and is not acceptable political behaviour in a ‘post-truth’ anti-expert age.