Mapping the Political Discourse in the Brazilian Chamber of Deputies: A Multi-Faceted Computational Approach

TL;DR

This paper presents a comprehensive computational framework for analyzing parliamentary discourse, revealing stylistic shifts, agenda changes, and identity-based alignments in the Brazilian Chamber of Deputies over two decades.

Contribution

It introduces a novel, scalable method combining stylometry, topic modeling, and semantic clustering to analyze political speech beyond voting records.

Findings

Speeches have become shorter and more direct over time.

Legislative agendas respond sharply to national crises.

Regional and gender identities influence discourse more than party affiliation.

Abstract

Analyses of legislative behavior often rely on voting records, overlooking the rich semantic and rhetorical content of political speech. In this paper, we ask three complementary questions about parliamentary discourse: how things are said, what is being said, and who is speaking in discursively similar ways. To answer these questions, we introduce a scalable and generalizable computational framework that combines diachronic stylometric analysis, contextual topic modeling, and semantic clustering of deputies' speeches. We apply this framework to a large-scale case study of the Brazilian Chamber of Deputies, using a corpus of over 450,000 speeches from 2003 to 2025. Our results show a long-term stylistic shift toward shorter and more direct speeches, a legislative agenda that reorients sharply in response to national crises, and a granular map of discursive alignments in which regional and gender identities often prove more salient than formal party affiliation. More broadly, this work offers a robust methodology for analyzing parliamentary discourse as a multidimensional phenomenon that complements traditional vote-based approaches.