The document discusses different media models and how the media shapes public opinion. It presents two media models - old media which includes newspapers, network TV, radio and magazines that had gatekeepers and aimed to be objective and factual, and new media which includes the internet, cable, blogs and direct mail that is non-hierarchical, slanted and opinion-based. It then questions how much power the media has to shape public opinion and lists some factors that limit media influence, such as political socialization, selectivity, needs, and recall and comprehension.