The arrival of guest workers in Denmark from the late 1960s meant new political questions of how to receive their children in school. During the 1970s, the heyday of welfare state reforms, a new area of welfare state politics and policy emerged concerning these children: an education politics of migrant pupils accompanied by knowledge being produced in the intersection between the pedagogical professional field, the academic field and the political field. This politics, policy and knowledge area soon became contested among politicians, professionals and academics. The article explores a core discussion still taking place at present, namely how approaches for receiving newly arrived pupils in the Folkeskole (the primary and lower secondary school. Based on source material consisting of parliamentary debates from the official political field and the professional and research-based literature that developed in the period, the article sheds light on how educational knowledge on different approaches to reception was circulated between fields. Executing an analysis that combines concepts from sociology and history of education and knowledge and from theory on policy processes, the article shows how knowledge and politics interacted to make or reject policy junctures in the formative decades when the politics of migrant pupils in the Danish welfare state was established, namely from the early 1970s and up until the mid-1990s. We conclude that local developments and debates in the knowledge production field shaped early school integration policies in the Danish welfare state during the 1970s and 1980s, but had limited influence in the 1990.