Any of you who think commercial networks are in it to enhance your understanding of the world at the expense of their advertisers’ mandate to sell product are misguided. Every commercial network’s customer is the advertiser, not the viewer. Viewers are only there to shape demographic sales data for advertising. 

This has been true since the demise of the Fairness Doctrine in 1987. If you are unaware of what the Fairness Doctrine was and how it helped keep media balanced (and truly journalistic), see this:

FCC Fairness Doctrine

So it’s a massive waste of time to even discuss any commercial network’s accountability with respect to journalism. Or to even try to characterize their bias as “left” or “right”. Or to even characterize their “bias” as bias to begin with. The term “bias” would be applicable if they actually cared about a particular world view. They don’t. What they care about is making sure the numbers they base their airtime commercial rates on are accurate. That means they care about packaging a predictable viewer response to advertising. Viewer ideological response to stories is less important. There may well be a number of “news directors” or “producers” on the news team that DO have a political agenda, but they were not hired for that. They were hired to keep the demographic data sellable and predictable. 

Newscasts and all the on-air talent they employ should be viewed as loss leaders - they are there to make content that will get you into the store to look at the commercials and provide data for the people who sell airtime and predictable results to the advertisers. If you expect something more journalistic, you need to look to media outlets that are funded non-commercially.