Book excerpt: Understanding why individuals participate in politics demands attention to more than just individual attributes and attitudes. Similarly, understanding how interest groups influence policy-making demands attention to more than just the financial donations and direct activities of Washington-based lobbyists. 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, Kenneth Goldstein develops and tests a theory of how tactical choices in a grass-roots campaign are made. In doing so, he demonstrates that outside lobbying activities deserve a place in any correctly-specified model of interest group influence, political participation, or legislative decision-making.