“Not Fissures but Moments of Crises that Can Be Overcome”: Building a Relational Organizing Culture in Community Organizations and Trade Unions * MAITE TAPIA Community organizations and trade unions rely to a certain extent on a commit- ted membership to be effective. It can be difficult, however, to build solidarity when there are diverse members with competing interests and this can lead to internal conflicts. Based on participant observation and interviews, this article examines how membership organizations have been able to maintain an active grassroots base and overcome internal crises through the development of a rela- tional organizing culture. Introduction There has been a remarkable rise in social movement activism in recent dec- ades—from worker centers, community organizations, the occupy movement, and new insurgencies in traditional unions—but the sustainability of many of these organizations is often fragile and the ability to maintain an active grass- roots base over time is problematic. To remain vital, membership organizations need to build solidarity within as well as across their social networks, develop affective ties among their members, and share cultural values and practices (Taylor 2000). Whereas historically, unions were created based on pre-existing solidarities, centered, for example, around specific skills, currently this is no longer the case (Gumbrell-McCormick and Hyman 2013). Defined in many different ways, solidarity often refers to feelings of belonging to the same group and *The author’s affiliation is Michigan State University, East Lansing, Michigan. E-mail: tapiam@msu.edu. This article would have not been possible without the support and time of people from the Greater Boston Interfaith Organization. The author also wishes to thank Lowell Turner, Lena Hipp, Rosemary Batt, Christian Ibsen, Peter Berg, Felice Klein, Mevan Jayasinghe, Tashlin Lakhani, the reviewer, and editor for their excellent comments on earlier drafts. INDUSTRIAL RELATIONS, DOI: 10.1111/irel.12229. © 2019 The Regents of the University of California Published by Wiley Periodicals, Inc., 350 Main Street, Malden, MA 02148, USA, and 9600 Garsington Road, Oxford, OX4 2DQ, UK. 1