Donald Trump want you to hate the media. He tells you they're "fake" and that they make things up. He repeats it over and over on Twitter, in press conferences, in interviews, and at post-election rallies.
The aim of this is simple. He is losing the one contest he cares about, popularity. His approve rating keeps dropping and his administration continues to lose members.
The only success he's ever obtained in life is by talking to those who are already convinced and then letting them do the work for him. He is a promiser, not a promise fulfiller.
In the business world, he's always controlled the message. He controls the board meeting, he controls the agenda, he controls the message. If anyone disagrees with his message, he can fire them.
The media, with that pesky 1st Amendment of the Constitution, are not so easily silenced. He can't fire them, he can't silence them. Instead he is trying to discredit them.
Though this is a common tactic of dictators, it it quite unlikely he is attempting to be a 21st century Hitler. More likely, he just wants to control his message, image, and popularity. He wants you to believe he is the only reliable source of information so you won't go to or trust other sources. Especially sources who might accidentally compare his claims to reality and find they are contentious points of view.
Today he is at a rally, funded by his election campaign, to deliver his "alternative facts" directly to those who already agree with him.
The point is, he will continue to attack reporters and you must not accept his lies. When he calls them "fake news" ask for proof. The media uses evidence when they report on things. This fool should present evidence when he tried to discredit them. Otherwise he is a lying enemy of the 1st Amendment.