First, the media, which is primarily associated with news programming, is only able to influence anyone to the degree that the viewer or listener chooses to be influenced. Those who choose to watch or listen to their news and then make their own inferences and draw their own conclusions will not be as likely to be influenced by the media as those who assume everything they hear or see is true.
Second, the number of possible news stories in any given day is enormous; because of social media and other outlets, these stories are also generally accompanied by something visual. A photograph, an audio clip, or a video all have the power to significantly increase the impact of any news story.
Because of that, he media has the great potential to try to influence any groups or races of people simply by the stories it chooses to air. If, for example, the media source wants to get Hispanics to hate the police, it might feature stories of police brutality toward Hispanics, accompanied by horrific video, of course. If the media source wants to encourage college students to blame Congress for the increased cost of their education, it might feature a series of stories which show Congress's refusal to lower the cost of student loan interest; by sheer repetition, the point can be made.
Rather than using overtly inflammatory language or making incendiary comments to influence a group of people, the media simply inundates its programming with stories which support the point of view it wants to promulgate. This use of selective programming/storytelling is used by both the left and the right to influence its viewers and listeners toward a particular position or ideology.
The media once had to work very hard to gather and deliver news from around the world in a timely fashion. Now nearly everything that happens can be quickly documented and aired; however, often in an effort to be first or to somehow influence its audience, stories are aired which are not really news or not really true.
This instant access has allowed the media to bombard its audiences with anything it chooses, and what it chooses to air is representative of the point of view it wants to reflect. This is how the media attempts to influence its audience.