Agenda-setting is a process by which public attention is directed toward certain problems or attributes, as issues worthy of concern, and away from others (McCombs 1993). By deciding what issues to cover and how to cover them, the media sets the public agenda, which in turn influences the importance the public attaches to various issues (Terkildsen and Schnell 1997). Furthermore, through the process of priming, the media elevates certain issues over others and, in so doing, influences what criteria are used by members of the public to judge political actors, their actions, and their policy offerings. By focussing accounts of criminal justice policy on the leniency or toughness of sentences or conditions of confinement, for instance, the media focusses public attention on that criterion instead of other measures such as effectiveness or cost --- indicators that might lead the public to demand alternatives to the current and spectacularly unsuccessful practice of relying on greater harshness to curb crime.

Priming and agenda-setting occur through a number of mechanisms. Journalists can become involved in a self-generated cycle of issue coverage as they become sensitized to issues with which they are familiar. By producing more on the same theme that they or a competitor have already covered, journalists can create a wave of news stories on one issue, making it seem that the problem, rather than the coverage, has increased (Protess, Leff, Brooks and Gordon 1985). In addition, easy access to particular sources can also have the effect of elevating one elite’s agenda over its rivals in the competition for the public’s attention and support. Crime stories, for instance, besides possessing the obvious advantages of being well received by the reading and viewing public, are also inexpensive and easy to cover because the police can be relied on as convenient and primary sources for stories. This gives them privileged access to the media compared to other interested parties with competing points of view. As a consequence, police have a sizeable advantage over other contenders in forming and shaping public opinion in ways that support their goals and agenda. In Canada, for instance, the government placed significant resources intended for reducing illicit drug demand (in addition to the sizeable expenditures aimed at strengthening their enforcement capacity) under police purview, thus strengthening their role in drug education and abuse awareness programs for youth, and establishing their “expert” credentials at both ends of the issue. In this way police sources enjoyed a substantial advantage in signifying the drug problem for the Canadian public.

While agenda-setting and priming describe which issues enter the public discourse and how they influence political decisions, issue framing can also influence public attitudes and levels of support. Issue frames--what is left in the stories and what is taken out--present a constructed reality that eclipses other avenues of interpretation. By defining and simplifying a complicated issue through framing, political actors direct voters to use a particular set of considerations, and ignore or dismiss others, in formulating their political preferences. The elite constructed frame interacts with an individual’s memory so as to prime these same considerations, making them more accessible than others in memory and, therefore, more likely to be used in formulating a political choice (Koch 1998). As Jacoby (2000) points out, powerful political elites have resources that give them the inside track on framing controversial issues for the public in ways that put their definition of the problem and their preferred solution in the best light.

Iyengar and Lenart (1989) found that various frames used in news coverage play an important part in shaping voters’ attributions of political responsibility as well as their preferences for solutions. Stories characterized by “episodic” news frames that focus on specific incidents--the way in which crime is most often reported in the news media--are more likely to elicit attributions of individual responsibility than are “thematic” stories that place social issues in a wider context of historical and other social developments.

Another study found that a racial frame significantly affected Americans’ policy preferences: “A mere five-second exposure to a mug shot of African-American and Hispanic youth offenders (in a 15-minute newscast) raises levels of fear among viewers, increases their support for “get-tough” crime policies, and promotes racial stereotyping” (Gilliam and Iyengar 1998:46).