> The 'Russian collusion case' has been thoroughly discredited
No, "collusion" doesn't exist as a crime. It wasn't discredited it just doesn't exist as a criminal thing.
And it turns out that "conspiracy" is something that requires the participants to understand that they're doing something wrong, and Mueller couldn't find any evidence of that. When you're rich and committing white collar crimes then the defense of "I didn't know it was illegal" apparently works, unlike us plebs when we get pulled over by the traffic cops.
There was plenty of evidence of coordination between the Trump campaign, Wikileaks and the Russians. Just none of it was considered crimes by the Muller investigation. Wikileaks was actively lending support to the Trump campaign in order to attempt to get Trump elected and defeat Hillary. So were the Russians. That is on solid factual ground. But Mueller didn't find anything there that the DOJ could charge him over.
It is also pretty clear that Mueller thought that the revelations would be shocking enough that Congress would impeach and remove Trump for what he had done and that "high crimes and misdemeanors" (which really has no legal definition) would cover it, but he didn't expect Congress to abdicate its responsibility in favor of partisan politics.
This is the same President that bragged he could "I could stand in the middle of Fifth Avenue and shoot somebody" and get away with it, and that is precisely what the Republican led Congress allowed him to do.