Debates about the impact of public opinion on public policy are organized around a “should” and an “is.” Almost everyone agrees that in a democracy public policy should be strongly affected by public opinion. “We often gauge the quality of democratic government,” Erikson, Wright, and McIver (1993:1) write, “by the responsiveness of public policymakers to the preferences of the mass public” (see also Manza and Cook 2002a:630). But there is a lot of disagreement about how strong the effect is. Is it as strong as it should be, meaning that the democratic political process is working well? Or is it much weaker, meaning that the democratic political process is working badly?

The past couple of decades have favored the “strong effect” view. Most studies show opinion influencing policy; some show its impact to be extremely powerful (Burstein 2003; Erikson et al. 1993; Erikson, MacKuen, and Stimson 2002). But a counterargument has emerged. Benjamin Page (2002), long seen as a proponent of the strong effect view, has reversed course and now argues that key studies overestimate the impact of opinion on policy. One reason, he argues, is sampling bias. Public opinion polls focus on issues important to the public – the very issues on which the public is most likely to hold elected officials accountable, and on which, therefore, democratic governments are most likely to do what the public wants. Other scholars have begun to express the same concern (Jones and Jenkins-Smith 2009:54; Lax and Phillips 2012:150).