Agenda-setting
An important role which is often ascribed to the media is that of agenda-setter. Wasserman describes this as "putting together an agenda of national priorities — what should be taken seriously, what lightly, what not at all". Gary Wasserman calls this "the most important political function the media perform." Agenda-setting theory was proposed by McCombs and Shaw in the 1970s and suggests that the public agenda is dictated by the media agenda.
Read more about this topic: News Media (United States)