To understand the background behind Trump's continued attacks against the free press and individuals' freedom of speech it's necessary to recognize he's using populist political strategy that ignores the Constitution when it stands in his way.
By treating critical media, institutional oversight, and political dissent as partisan opposition rather than protected democratic rights Trump has polarized the country. His agenda calls for daily attacks against people's rights to remind them he's in charge.
Dictators don't like any kind of opposition and Trump has proven beyond a doubt that he worships dictators (think the recent Xi visit) and wants to emulate their control over the entire country and culture.
With that being said there's more to Trump's loathing of free speech. As a malicious narcissist he takes unfavorable news coverage as a direct attack on his public image. He's as thin-skinned as a reptile and twice as venomous when he's throwing tantrums.
Another reason Trump goes after free speech in any form is it distracts from his alternate realities and daily lies. By threatening and intimidating the media that doesn't praise him he's seeking control of the national dialogue and directing it down a narrow path that pleases him.
There's also an element of fear when it comes to muzzling media stories. Trump is afraid people will see the harsh realities surrounding their lives throughout the entire country and question his propaganda. Given the choice Americans expect the news media to tell the truth instead of being a vehicle for state sponsored lies.
While Trump has branded himself and his allies as defenders of free speech against institutional "censorship," critics argue that his actions demonstrate a pattern of using executive power to suppress speech he disagrees with.
Ironically Trump and his defense teams have conversely used the 1st Amendment as a primary shield. For instance, in criminal election-interference indictments, his lawyers have argued that his claims regarding a "rigged" election are protected speech.
However, legal scholars and prosecutors maintain that the 1st Amendment does not protect speech used as an instrument to commit a crime, such as pressuring officials to alter election results. Something we're seeing a lot of prior to the upcoming midterms.
As it Stands, following the standard agenda for rising dictators, Trump understands what an enemy free speech is to his regime.