Trump should refuse, and he should order Sessions to appoint a second special prosecutor as I wrote above. This is so obvious I am surprised it is not already being pushed for. Mueller is conflicted deeply. He has appointed associates who are conflicted deeply. Too many appearances of impropriety. He must be put into check. His investigation must be investigated. Is the Mueller investigation being used to whitewash and cover-up the crimes of people inside the agency he once led?
He cannot claim clean hands. He never could but now given what we know about McCabe, Sztrok and the treatment of the Uranium One informant just to name a few - plus the odd fact that he is only investigating collusion against Trump when everyone knows the connection with Clinton to Russia and Ukraine among others - it makes no sense. It is like trying to stop police corruption by investigating a few people suspecting of paying off the cops.
Obviously they are trying to box Trump into a corner - where they hope to destroy him. Since it is obvious that the Dems run the country, the solution may be a civil war, forced by the Left, where the people re-exert their sovereignty. Let's hope it doesn't come to that.