ABSTRACT In July 2018 the Twitter hashtag #secondcivilwarletters began trending as part of a collective response to conservative media personality Alex Jones’ warning that Democratic supporters were planning to launch a Second Civil War on Independence Day. The response consisted of tweets in the form of parodic letters written as though they were from the American Civil War period, and engaged in a collective form of political commentary and discussion, mostly displaying an anti-Republican and anti-Trump sentiment. This article analyses the (...) different ways the tweeters used Twitter and the #secondcivilwarletters hashtag to engage in the humorous discursive delegitimisation of President Trump and Republicans. It was found that the strategies of authorisation, moral evaluation, rationalisation, and mythopoeisis featured prominently in the tweets and, combined with the humorous edge, nourished the political participation and discourse of this online community. (shrink)