According to the Washington Post Trump was told, on January 6, two weeks prior to his inauguration, that the CIA had specific knowledge of Putin’s direct instruction to hack the 2016 election


Following a rehearsed plan, Clapper functioned as moderator, yielding to Brennan and others on key points in the briefing, which covered the most highly classified information U.S. spy agencies had assembled, including an extraordinary CIA stream of intelligence that had captured Putin’s specific instructions on the operation.


What I find most interesting is this passage


The officials had already briefed Obama and members of Congress. As they made their way across Manhattan in separate convoys of black SUVs, they braced for a blowup.



“We were prepared to be thrown out,” Clapper said in an interview.



Instead, the session was oddly serene.


It is almost as when you are telling someone that their relative died, expecting an emotional response, but getting only a blank stare, as if they already knew, as it they might have been involved?

It would be defensible to for Trump to say that Putin’s involvement had no direct impact on the 2016 election.  This appears to be consistent with US intelligence conclusions, even though most of think those conclusions are faulty.  However, Trump has said, repeatedly, that he believes Putin that Putin had no involvement at all.  This is counter to all US intelligence conclusions.  

We now know that Trump knows that Putin directed the hacking of the election, and that Trump is participating in a cover up in participation with Putin.  In other words, collusion to subvert the US democracy.