The core issue is that a former and quite possibly future president is accusing many influential members of the other party of very serious crimes and stating without any subtle nuance that the justice system is compromised and Americans cannot trust it.
These are enormously serious allegations and yet the media just choose to be cheerleaders for the criminal enterprise that is the current administration and its supporting cast, in fact, just about all of the Democratic Party. This rot likely extends well into the Republican Party as well.
I find it astonishing that these matters have not created a political response beyond the indignation of Trump’s base of support. The role of the media in this cannot be excused. It is another crime of great significance rivalling the crimes that they refuse to investigate or report on.
Which is to say it appears he believes he holds compelling evidence that will "clean out the swamp".