If you repeat a lie often enough, people will believe it. Or, the more you repeat that lie, the more people will start to accept it as truth. In Trump's case, he tweets repeatedly that the liberal media is "fake news", and that that is "the dishonest media". He does the same at every one of his rallies. To any objective observer, its long been obvious that Trump's definition of "fake news" is any news that does not cast him in a good light. If it's critical of him, if it relates information that may be damaging or may represent stuff he would rather not see related, it's "fake news". That is far from an objective standard. Indeed, that is propaganda.
Two of the best known examples of fake news were in fact promolgated by the Alt Right and conservative outlets like Fox News. Recently, Trump retweeted something tweeted by an alt right activist who in fact pushed those two discredited fake stories: Pizzagate on the one hand, and the murder of Democratic activist Seth Rich on the other hand:
http://abcnews.go.com/US/trump-retweets-alt-activist-pushed-pizzagate-conspiracy/story?id=49221083
Trump just does not have high standards where truth is concerned. Pizzagate is well known enough. If one needs a refresher course on the Seth Rich bs conspiracy theory, here you go:
https://www.vox.com/policy-and-poli...-conspiracy-theory-explained-fox-news-hannity
Fox eventually stopped promulgating this fake news story. I'm not sure if Sean Hannity continues to promote it on his radio show or not.
In any event, it's remarkable, at least I think so, that Trump utilizes the fake news meme to condemn any media outlet that publishers the truth! It's kinda diabolical, in that respect. And it has worked. An alternative universe has been created, not simply by Trump alone, he has had plenty of help from the Alt Right and conservative media outlets, but he has continually reenforced this narrative whenever he speaks to his base. And he pretty much only speaks to his base.
I have a close friend who supports Trump. He told me the other day that Trump was correct in saying there were "fine people" in the Friday night torch led march of people chanting "Jews will not replace us.", the night before the Charlottesville rally. I told him if he watched footage of that march, which I had saved, and would be happy to show my friend, and saw everyone chanting that, as well as chanting "Blood and Soil", and if he would still tell me some of them were "fine people", (my argument being what kind of "fine people" join such a march and chant those things in the first place), he refused to watch the footage, telling me "it's all fake news. I don't have to see it. It's fake".
And that, I submit, is what it has come to. Trump has repeated the "dishonest media" lie so often, to his base, that they no longer find it necessary to even so much as glance at the facts. Facts and Truth are beside the point. His base is comfortable and completely at ease living in their fake universe.