https://doi.org/10.1177/0895904817719516 Educational Policy 1–33 © The Author(s) 2017 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0895904817719516 journals.sagepub.com/home/epx Article Interest Group Activity in the Context of Common Core Implementation Jonathan Supovitz 1 and Patrick McGuinn 2 Abstract This article analyzes the messages and strategies of a sample of education interest groups, and assesses their interpretations of the political context to understand how the Common Core State Standards (CCSS) lost both political and public support during the crucial period of 2013-2014. Based on interviews with representatives of 19 interest groups who were actively involved in communicating about the standards, it focuses on the arguments, communication strategies, and targeted audiences of professional advocacy groups, policy membership organizations, and testing organizations. Our findings identify six themes that contributed to the climate of increased partisanship and politicization, and helped shape perceptions about the Common Core, both within the education sector and among the broader public. We argue that these policy factors, strategic factors, and contextual factors played an important role in shaping the environment within which the CCSS were being understood and implemented. Keywords educational policy, education reform, politics of education, Common Core 1 University of Pennsylvania, Philadelphia, USA 2 Drew University, Madison, NJ, USA Corresponding Author: Jonathan Supovitz, University of Pennsylvania, Philadelphia, PA, USA. Email: jons@upenn.edu 719516EPX XX X 10.1177/0895904817719516Educational PolicySupovitz and McGuinn research-article 2017