Its quite obvious that Lindsey Graham takes advantage of a media that has no interest and curiosity about some things.
Hes always promising Hearings and Judgement day, but does nothing year after Year.
Theres a common sense expression: actions speak louder than words.
Just follow what he does - and its all crystal clear.
Besides all the above, what earthly use would it be to have Mueller come and testify? He already testified in front of Congress. What do they want to hear? “Yes, I hired all Demshevik lawyers. Yes, they made a few stupid and in most cases illegal (as in Flynn’s cawe) arrests based on lying bullsquat from corrupt Fibbers who are now gone. I really didn’t do much, Weissman pretty much ran the show.”