The present thesis uses methods of Critical Discourse Analysis to examine 16 front-page newspaper articles, from The New York Times and The Washington Post, covering progressive presidential candidate Bernie Sanders during the 2015 “invisible primary”. In particular, this thesis investigates how Sanders and his supporters were represented, linguistically and visually, and whether these representations – formulated as “interpretive frames” – appear more legitimizing or delegitimizing. In the crucial prevoting period of the invisible primary, the media largely have the power to construct the identity of relatively unknown candidates, such as Sanders, in the minds of the national public. The 2015/16 election season occurred against the backdrop of extreme levels of economic inequality and related societal ills, which have arguably arisen from four decades of neoliberal policies implemented by successive American presidents from both major political parties. The findings of the analysis appear to confirm a concerning pattern of largely delegitimizing US media coverage (or omission) of progressive political candidates and social movements going back several decades. In the articles analysed, Sanders was represented using interpretive frames casting him as an extreme leftist, angry and impersonal, or marginal and old. Only one major interpretive frame – representing him as a skilful, pragmatic politician – appeared legitimizing. Similarly, Sanders’ supporters were largely framed as activists, excitable fans, or divided into narrow identity categories (e.g. “white liberals”) that appear delegitimizing when considered opposite the shared economic struggles that many of them likely face. Given the liberal reputation of The New York Times and moderate image of The Washington Post, the results raise further doubts about the ideological diversity of the mainstream American public sphere.