"""Americans continue to register record-low trust in the mass media, with 31% expressing a “great deal” or “fair amount” of confidence in the media to report the news “fully, accurately and fairly,” similar to last year’s 32%. Americans’ trust in the media -- such as newspapers, television and radio -- first fell to 32% in 2016 and did so again last year."""
https://news.gallup.com/poll/651977/americans-trust-media-re...
And these stats hold for liberals as well; they feel their outlet isn't the "MSM", but that Fox is and is untrustworthy.
Since the job of news is now to sell ads and not tell the truth, a lot of "supporters" only hear what their side wants them to hear, and not the facts.
The real problem of course is that each party has different policies; but if we as citizens don't agree on the facts and problems facing us, then there is no way to evaluate the strength of the policies against the problems.