Diffusion of democratic regression occurs when incidents of democratic backsliding abroad increase the likelihood and magnitude of democratic backsliding at home. We have elsewhere found strong evidence that democratic regression diffuses on a global scale. In this paper, we develop two key domestic mechanisms of the diffusion of democratic regression. We argue that observing external precedent of democratic regression emboldens anti-liberal domestic actors by making anti-liberal reform appear (1) more normatively appropriate and (2) more programmatically effective (Ambrosio 2010). The mechanisms affect both political elites and voters, increasing the electoral supply of and demand for anti-liberal reform, and ultimately the likelihood and intensity of democratic regression. We focus on elites in this paper. We provide a mixed-methods analysis to bolster our argument. We estimate Bayesian spatial-x models to show the general effect of external backsliding precedent on anti-liberal electoral supply, i.e. the number of anti-liberal electoral parties and the degree of their anti-liberalism. In qualitative and computer-assisted (LLM) text analyses of parliamentary debate and state-of-the-union type speeches of heads of government, we trace narratives of appropriateness and effectiveness of external backsliding precedent and examine whether and how the two mechanisms appear in political justifications for reform that lead to democratic regression. We compare two most-likely and most-different cases to strengthen the generalizability of the mechanisms. Preliminary findings provide support for our argument that external precedent emboldens anti-liberal domestic actors in processes of democratic regression.