Sweden has experienced increasing educational inequity levels within its highly decentralized school system. With a reduced capacity to bargain collectively, the two Swedish teacher trade unions, the Swedish Teachers' Union (Lärarförbundet) and the National Union of Teachers in Sweden (Lärarnas Riksförbund), have sought to extend their role in social unionism. This interpretive study explores the discourses of professionalism on which both unions draw to reframe the narrative around issues of social justice and democracy. Using sociological and institutional theories, policy documents were analyzed to understand processes of theorization in the legitimation of change.