This study investigates how U.S. Fortune 500 corporate social advocacy (CSA) discourse on multiple contentious issues is associated with public attention on Twitter/X. Our theoretical framework elucidates three discourse types and conceptualizes the diversity, structure, and stability of discourse coalition networks. Utilizing computational methods and dynamic network analysis of 43,791 corporate tweets over two years, findings reveal a prevalent use of aspirational communication in addressing climate change and healthcare disparities. Functional discourse is predominantly employed in tweets on racial equality and COVID-19 vaccination, while localization discourse is concentrated in tweets about gender/sexuality. Network analysis shows that discourse coalitions exist across industries, with a convergence in discourse types and low temporal stability in network compositions. Most discourse types and features of discourse coalition networks are positively associated with public attention to CSA tweets, though these associations vary across different issues.