:: there very well may be a prosecutable case, but inferred that it would be up to Congress to pursue. ::
Congress has NO prosecutorial power. They can only refer (to the DOJ) for investigation and possible indictment. In impeachment, the Senate prosecutes.
They are stuck.
Good points. The Senate would require how many votes?
So referring to the doj makes it even worse, they will say Barr is protecting the President. What a #### show