All they have is hammering McGahn and what he states was said and done. One person. How does the President defend against that?
But it appears that the Democrats' plan is not moving forward. Their goal with Mueller is to make a case that the House needs to continue the obstruction investigation-that Mueller was handcuffed by DoJ policy that wouldn't allow for an indictment of the president.
It sounds as though Mueller and the Democrats aren't even making the case that the investigation was onto anything. They are extremely far from offering any probable cause of an obstruction charge.