Public debate is commonly understood as deliberation; as the weighing of arguments for and against choices of future action. A principle of deliberation entails that interlocutors approach one another through argumentation in favour and against a given point of view. In this article, I outline a competing debate ideal, the principle of expression, and demonstrate its pervasiveness in contemporary public rhetoric. According to this communicative ideal, public debate is understood not as an exchange of opinion but rather a display of opinions. The beliefs and opinions voiced in the public debate should, moreover, be seen as purely expressive: They arise out of the individual’s inviolable interiority and individuality. As such, argumentation is neither required nor legitimate. In the article, I outline the principle of expression and discuss its implications for the democratic public debate. I do so, by drawing on a case study of public debate in social media, as well as recent utterances spoken by political leaders. In moving between the utterances of ordinary people engaged in public debate in the informal setting of social media and the utterances of political leaders in formal settings, I demonstrate the pervasiveness of the principle of expression in contemporary public rhetoric.