What does it mean to speak presidentially?

US President Donald Trump’s recent speech to a joint session of Congress received positive feedback from some of his most vocal critics. Taking a variety of texts by way of comparison – including selected speeches of former US Presidents Barack Obama and Richard Nixon – we will discuss how the resources of language contributed to making Trump’s speech to Congress come across to critic and friend alike as ‘presidential’. Halliday’s Systemic Functional Linguistics (SFL) which prioritizes the study of function over form, provides the theoretical and methodological basis for investigating ‘the aesthetic and functional values that differentiate one text from another, or one voice from another within the frontiers of the same text’ (Halliday Collected Works, Vol. 2, chapter 6, p.187). Rhetorical Structure Theory (RST), complements the clausal orientation of SFL by investigating the relations that occur between functionally-significant text spans at clause level and above.