We extend agenda building theory by integrating social movement and connective action research to explain how marginalized groups elevate issue salience. Our framework comprises three dynamics: exogenous conditions (key events & real-world indicators), interpublic processes on social media, and intermedia processes between news and social media. We apply this framework to the #StopAsianHate movement on Twitter/X using network and time-series analyses. Results show that the Atlanta spa shootings, a key event, intensified attention to anti-Asian hate among AAPI activists’ allies (liberals & K-pop fans) and elite media, whereas hate crime indicators had limited impact. AAPI activists had modest influence on other Twitter users and elite news, but their allies, especially liberals, proved influential. Elite media attention was driven by attention from both liberals and aggregate Twitter, with liberals’ effect lasting longer. The framework illuminates how key events, networked publics, and movement resources interact to build issue salience in digital media.