Why are some civic associations better than others at getting―and keeping―people involved in activism? From MoveOn.org to the National Rifle Association, Health Care for America Now to the Sierra Club, membership-based civic associations constantly seek to engage people in civic and political action. What makes some more effective than others? Using in-person observations, surveys, and field experiments, this book compares organizations with strong records of engaging people in health and environmental politics to those with weaker records. To build power, civic associations need quality and quantity (or depth and breadth) of activism. They need lots of people to take action and also a cadre of leaders to develop and execute that activity. Yet, models for how to develop activists and leaders are not necessarily transparent. This book provides these models to help associations build the power they want and support a healthy democracy. In particular, the book examines organizing, mobilizing, and lone wolf models of engagement and shows how highly active associations blend mobilizing and organizing to transform their members' motivations and capacities for involvement.