Representing the States Before the U.S. Supreme Court: State Amicus Brief Participation, the Policy-making Environment, and the Fourth Amendment

State attorneys general, situated at the intersection of the state and federal governments, are increasingly the subject of scholarly inquiry. Yet, little work examines what prompts them to participate as amici. The decision to participate as amici reveals important information about how state actors attempt to shape outcomes at the federal level. We investigate how the broader policy-making environment facilitates and constrains AG amicus brief initiation and joining. Analyzing all orally argued Fourth Amendment cases from 1970 to 2009, we find the characteristics of the policy-making environment shape AG amicus activity. Initiation is predicted by institutional resources; whereas joining is the product of legal case facts and institutional resources. Because prior research notes larger attorney general coalitions are more successful, we highlight the complexity of amicus participation by state actors and speak to the conditions under which state actors can mobilize large coalitions to shape federal search and seizure case law.