["Journal of Research on Adolescence, Volume 36, Issue 2, June 2026. ", "\nAbstract\nDuring the 2024 US presidential election, a surge in anti‐lesbian, gay, and bisexual (LGB) rhetoric contributed to a hostile political climate that intensified the psychological impact of discrimination among LGB young adults. Drawing from minority stress theory and the psychological mediation framework (PMF), exposure to LGBT discrimination may be linked to greater substance use through intrapersonal (sexual orientation rumination and hopelessness) and interpersonal (interpersonal political tension) processes. However, little is known about these indirect pathways and whether they vary as a function of perceived anti‐LGBT political climate. The present study tested two moderated mediation models in which exposure to LGBT discrimination was hypothesized to be related to alcohol and marijuana use through greater sexual orientation rumination, hopelessness, and interpersonal political tension and in which perceived anti‐LGBT political climate was expected to amplify the discrimination–mediator links. The sample consisted of 442 LGB young adults (40% Black, 27% Hispanic, 34% non‐Hispanic White; 41% Gay, 30.8% Lesbian, 28.3% Bisexual; Mage = 22.72, SD = 1.74; 18–25 years). Overall, LGBT discrimination showed significant indirect associations with alcohol use through greater sexual orientation rumination and interpersonal political tension, with the interpersonal political tension pathway stronger among those perceiving a more hostile political climate. For marijuana use, discrimination was indirectly associated with greater use through heightened hopelessness and interpersonal political tension, and both pathways were amplified in more hostile climates. These findings highlight identity‐focused rumination, hopelessness, and politically charged relational strain as important targets for efforts to reduce substance use among LGB young adults during contentious sociopolitical periods.\n"]