You are right that they are acting panicky. If they were relaxed, they would allow themselves time to marshal their evidence.
It's a shame the Republicans don't get to see the failure of their effort to distract from the main topic: the main topic is, is the President essentially a Russian agent? His team is the stalking horse.
Trump seems to be following the key elements of the playbook described by Christopher Steele. Does he own 19% of Rosneft? Did he sell America for a vast personal fortune?
Whether someone illegally publicised information about Flynn is a sideshow. No one would have set up a congressional committee to investigate that. It's a simple leak investigation.