For most observers, the election of Donald Trump as the 45th president of the United States (US) came as a shock. This has been widely recast as the culmination of the American public’s long-standing dissatisfaction with the political elite and deep-seated frustrations with broader socio-economic conditions. We argue that the Trump campaign’s success also stemmed from its effective use of an emotionally charged, anti-establishment crisis narrative. With insights from political psychology, we examine the socio-linguistic mechanisms that underlie the effectiveness of ‘Trump-speak’ through both quantitative and qualitative content analysis of Trump’s communications toolkit during the 2016 US presidential election campaign. We show that his leadership legitimation claims rest significantly upon ‘crisis talk’ that puts his audience in a loss frame with nothing to lose and explain why ‘crisis talk’ impacts on political behaviour. As we demonstrate, the crisis stories that political agents tell simultaneously instil ontological insecurity among the American public and serve to transform their anxiety into confidence that the narrator’s policy agendas are the route back to ‘normality’. Through these rhetorical mechanisms, the Trump campaign manipulated individuals’ ontological (in)security as a tool in the politics of reassurance at the broader, societal level.