Intraparty polarization on climate change in Republican Party discourse, 1987–2016

This study investigates how climate change became discursively polarized within the Republican Party between 1987 and 2016. While climate polarization is typically framed as a partisan divide, I show that discourse was more fractured within the GOP between its center-right and far-right factions than between parties, and more so than on other culture war issues. Using word embeddings, embedding regression, and qualitative analysis of over 800,000 congressional speeches, I identify a three-phase trajectory: early contestation between center-right internationalism and far-right climate denial; an asymmetric period when intra-party polarization exceeded between-party differences; and eventual convergence around a populist attack on elite bureaucratic overreach. This convergence is consistent with classical contamination dynamics, though it occurred not through the center-right adopting denial but through both factions arriving at a distinctly libertarian attack on the administrative state. The study bridges U.S. work on climate polarization with European scholarship on right-wing coalitional change.