Populist movements center around a strong political leader and focus on the distinction between ‘the people’ and ‘the elite’. As soon as populists gain government power, they are thus faced with an ideological dilemma: Suddenly, they themselves are the political elite. Continuing in this line of thought, the article aims to understand whether a change in political power affects how populists and their supporters engage in dialogue online. Assuming that populist practices differ depending on the degree to which the politician in question still adheres to the political establishment, the analysis compares tweets by Donald Trump and his supporters with tweets by Boris Johnson and his followers based on 727 tweets posted in two stratified constructed weeks before and after the respective politician took office. By focusing on dialogue practices of populists as well as their supporters in terms of converging or diverging pragma-rhetoric strategies, the article extends existing research on populism by adding the voice of those who conceptualize themselves as embodiment of ‘the people’ that populism evokes. The results show how person deixis and ethotic arguments in online dialogues not only establish a rapport between populist leaders and their followers, but also serve to form collectives that are intransigently opposed to each other.