To fire special counsel Robert Mueller by removing Jeff Sessions for a new attorney general to do the firing, as suggested by pundits such as Dana Perino ostensibly to help Trump, would be political suicide for the president these days, so the easy way out is to make Mueller look foolish by what would be uncovered by a second special counsel to investigate what Robert Mueller is surely ignoring, the Clinton Foundation and Russian collusion for the Democrats through the work of Fusion GPS for instance.
