In recent years, several major disasters, crises, and catastrophes have occurred in the United States and around the world. The September 11 attacks are the most consequential event of the 21 st century thus far, and changed the course of national and international history and policy in a way unseen since the outset of the Second World War. The September 11 attacks spurred a series of statutory, regulatory, and political changes, the effects of which continue to be discussed and debated to this day. But we need not look only to September 11 to see crises that spurred greater attention to problems and greater pressure for policy change. Events like the global financial crisis of 2008, and Hurricane Katrina in 2005, received intensive public interest in policies intended to regulate financial transactions and policies intended to mitigate, respond to, and recover from so-called natural disasters. These sudden crises are called "focusing events." Focusing events are an element of the agendasetting process, in which some issues gain and others lose attention among policy makers and the public. Agenda setting is interesting for political scientists because "the definition of the alternatives is the supreme instrument of power" (Schattschneider 1975, 66), where alternatives can mean issues, events, problems, and solutions. Groups-or advocacy coalitions (Sabatier, Jenkins-Smith, and Lawlor 1996; Sabatier and Jenkins-Smith 1999) engage in rhetorical battles, in different venues, to gain access to the agenda while attempting to deny agenda access to other actors (Cobb and Ross 1997; Hilgartner and Bosk 1988). Group competition is fierce because the agenda space is limited by individual and organizational constraints on information processing, so that no system can accommodate all issues and ideas (Walker 1977; Baumgartner and Jones 1993; Cobb and Elder 1983). This competition is over both which problems are most important, and over what causes and solutions surround any one problem (Hilgartner and Bosk 1988; Lawrence and Birkland 2004; Birkland and Lawrence 2009). The agenda setting process is therefore a system of sifting issues, problems and ideas and implicitly assigning priorities to these issues. John Kingdon (2003) argues that agenda change is