I believe Trey is the only one (from Congress) who has seen everything (Secret Docs). He knows where and how to find the evidence.
Theory: Upon learning first hand of the corruption in Govt and the plot against him, Trump with Sessions sign (in secret) a blanket Nat Sec surveillance warrant. A warrant covering every person or company that receives Govt money. This means Pols, Employees and Vendors would be covered. So basically everyone in or connected to Govt would be in the sights. Only the Pres can order a warrant without going to court.
Now they know every move before it even happens. All devices that the perps have and always been told are secure from surveillance have actually already been compromised. So the perps go to town with their plot thinking they are under the radar. When in fact they are telegraphing everything to the man. But they feel very safe.
When the FISA report was done and released to the perps early as required by law. Suddenly heads started to explode when they saw how effed they were. So Impeachment goes mainstream. A one sided process that will allow the perps to muddy the waters. Maybe, just maybe they also started to receive preservation of evidence orders from Barr or Durham.
So the only hope they have is to create enough hysteria to start a civil war that destroys Trump and they get a pass. There will be no civil war. Trump won before the battle started. But the wheels of Justice turn slow.