Argumentation and Language in Identity Construction: A Discourse-Historical Analysis of Polarisation in the 2024 Trump-Harris Debate

While Presidential debates present policy positions, they also construct group identities. This article asks how argumentative structures and linguistic choices work together to produce the “We” identity and “Them” identity that is characteristic of polarised political discourse. We analyse the 2024 Trump–Harris debate by integrating only argumentation schemes into the Discourse-Historical Approach (DHA) for its approach to argumentation. Three questions guide our analysis: how argumentation schemes construct in-group and out-group identities; how do lexical choices, analysed through DHA's nomination strategy, construct in-group/out-group identities; and whether patterned relationships exist between scheme types and discursive strategies. Drawing on 24 reconstructed arguments and six in-depth analyses, we observe that ad hominem attacks and poisoning-the-well arguments tend to co-occur with predication and perspectivisation strategies, while arguments from consequences tend to co-occur with justification. We term these patterned relationships schematic affinities and offer the concept as a hypothesis warranting systematic investigation rather than a confirmed finding. Lexical devices, including terms that categorise actors as criminals, victims, or workers, reinforce the opposition that arguments establish. The framework demonstrates how argumentation theory and Critical Discourse Studies can inform one another, and it opens pathways for research on national identity formation, racism, and discriminatory discourse.