As mentioned elsewhere on this blog, I am a big fan of Chomsky and Herman's Propaganda Model of the Media. The first of the five filters that make up this model concern the size, concentrated ownership, and profit-orientation of the media. The argument here is that these factors shape or filter the content of the media we receive in the US. A very good example of exactly this point comes from an episode of Last Week Tonight With John Oliver that first aired on July 2, 2017:
As an addition to John Oliver's analysis, a video recently surfaced showing how Sinclair is using its media empire to promote a particular point of view. Video and analysis of this can be found here.