In the cable era, television audiences fragmented into a 500-channel (or more) universe. The advent of the Internet further splintered the dissemination of information into thousands of outlets. Today, the very same media which used to unify us (at least with regard to communal experiences and a commonality of basic information), is now the force which most actively divides our country. As someone who lives in the Los Angeles market, where about half the radio and television stations do not even broadcast in English, I can personally attest to how dramatic this change has been.
Today, “Broadcasting” (other than the Super Bowl) no longer exists. It has been replaced by “Narrowcasting,” in which outlets are cynically designed to appeal to nothing but a tiny sliver of demographic for the purposes of maximizing advertising efficiency. This is destructive enough in the fantasy world of entertainment (no current TV show could even remotely claim to be well-known to a majority of Americans), but this has been absolutely catastrophic in the realm of news.
Almost all of our news outlets now can be easily identified as having a particular, and often very narrow, political bent and they act like nothing more than TV sit-coms desperately searching for a sellable demographic which will keep them afloat (see Breitbart.com & Donald Trump). This means that most “news” organizations are only interested in stories and truths that their audience will want to hear. Quite simply, nothing could be more antithetical to both the pursuit of truth (which is quite often very UN-popular) as well as the maintenance of a country which has enough “knowledge” in common so as to be able to function as remotely unified society.