Trump's ego is boundless. He can't tolerate information that threatens his inflated self image. Following the inauguration he has been highly critical of the media for reporting that the attendance at his inauguration was less than Obama's in 2009. The media showed photos of both events and it was obvious that there were more people at Obama's inauguration. That did no convince Trump. He sent his Press Secretary to press briefing in which he told them that they had misreported the attendance. He did not take any questions. This was his first meeting with the press and it set a new precedent. His purpose was to scold them following the president's order. That is not how press conferences have typically worked. His press secretary is going to have tough job. The press will not report information that is not supported by evidence.
That brings us to another of Trump's emissaries to the media. She was interviewed on national TV and held the party line on the attendance reports. She defended her position by arguing that facts are not facts. She claims that there are "alternative facts" that the Trump team uses to defend obvious falsehoods. This makes life tough for reporters. They can't rely on facts when alternative facts can be manufactured by a person who rejects facts that he does not like. Moreover, Trump uses these occasions to convince his base that they cannot not trust the media. He will provide them with alternative facts so that they do not have to question his majesty.
Democracy depends upon the press to evaluate and verify the information they are provided by government officials. Consequently, politicians are often critical of well trained journalists who try to do a good job. Trump has taken that conflict to a new level. There is no such things as facts and the media who challenge him with facts cannot be trusted. Its not surprising that Trump prefers using Twitter which does not check his statements for fact, and that he prefers fake news sources that provide his base with the information that they want to hear. Fox News and talk radio have historically played that role but the social media have made it easier for people to choose the information that they want to obtain and reject other sources. This does not auger well for democracy.