Final answer:
According to the 'marketplace of ideas,' various opinion leaders such as politicians, pollsters, policy specialists, activists, and journalists are responsible for shaping public opinion.
Step-by-step explanation:
According to the 'marketplace of ideas,' the responsibility for shaping public opinion lies with various opinion leaders such as politicians, pollsters, policy specialists, activists, and journalists.
These individuals are considered to be political elites who have the knowledge and capabilities to promote policies and shape public opinion.
The views and interpretations of these opinion leaders are conveyed to the public primarily through mass media, which plays a significant role in influencing public opinion.