Circumstantial evidence is too easily talked away and his base believes him. 
So true Gump. I've given up on his base. Nothing will change them. But you're right about circumstantial evidence. This in Congress who are sheltering Scrotus will be only too glad to argue it away. We need something definite that will stick. A smoking gun.
It's what I've always worried about. That Scrotus has been canny enough to put so many layers between himself and illegal activities that nothing will ever point directly to him.