More than individual attributes and attitudes motivate individuals to participate in politics and more goes into interest group influence than financial donations and direct activity. To answer fundamental questions about what determines when and why people participate in politics and how organized interests go about trying to influence legislative decision-making, we must understand how and why political leaders recruit which members of the public into the political arena. Looking from the bottom up with survey data and from the top down with data from interest group interviews, Goldstein develops and tests a theory of how tactical choices in a grass roots campaign are made.