— Donald J. Trump (@realDonaldTrump) February 25, 2017
“FAKE NEWS media knowingly doesn’t tell the truth. A great danger to our country. The failing @nytimes has become a joke. Likewise @CNN. Sad!”
Essentially, labelling an entire newspaper or media outlet “fake” is tantamount to a smear campaign. President Donald Trump cannot control what they say, so instead he tries to control how the public perceives them, particularly when they are pointing out his mistakes or lies. Stating that they are fake and failing is further “baiting” them into reflexively defending themselves.
Name-calling is a common tactic when someone cannot make a respectful, convincing rebuttal.