Trump is a proven liar/manipulator. He's attacking the free press to discredit it so it can't hold him accountable. Any critical coverage of him is deemed as "fake news."
Russia did most of the work. Trump was given an easy task
1) On June 9, 2016, Trump Jr, Manafort & Kushner met Russians who promised election help.
2) On July 27, 2016, Trump called for Russia to hack