This project investigates how political parties in liberal democracies adjusted their rhetorical commitment to liberal international norms (LINs) following the sudden autocratization of a liberal great power—the United States—under the Trump administration. Conventional wisdom suggests that liberal democracies should condemn foreign autocratization and uphold LINs, yet empirical evidence remains inconclusive. Existing research shows that far-right success entices mainstream parties to converge their positions on related issues, but it is unexplored if the conclusion can be extended to foreign events. Drawing on scholarship on autocratization, norm diffusion, far-right politics, and party strategy, this paper hypothesizes that the autocratization of the U.S. under Trump administration heightened the salience of issues related to LINs such as immigration, climate change, and LGBTQ+ rights, generated more negative sentiments among right-wing and governing parties, and encouraged the diffusion of Trump-like rhetoric challenging LINs. The study employs a comparative quasi-experimental design, using Trump’s electoral victory and inauguration as exogenous shocks. It analyzes parliamentary speeches from parties in the United Kingdom, Sweden, and Japan through state-of-the-art quantitative text analysis to measure the shifts of issue salience, sentiments, and rhetoric over time.