The Mueller investigation was targeted toward Trump. The investigation was not allowed to diverge, to crimes unrelated to Trump's assumed guilt. Mueller was not commissioned into looking into the role of Obama and Clinton, unless Trump made a deal directly with them, and Trump could be attached to that crime. Barr has said he will now make a new targeted investigation, that targets the front end; Democrat characters, who began the scam. How did this 2 years of collusion delusion begin?
There is the IG; inspector general report, on FISA abuse, in the works. The technical problem with this report is, the IG can only investigate active government employees. Many of the criminals involved in the abuse; i.e., Comie, don't work for the government any longer. They cannot be questioned, because they are private citizens. The IG report may not be conclusive, based on the private-public employee protocol. Barr will use this report, as a start, and expand it to include the guilty private citizens not questioned.
The collusion delusion and how it fooled the left, can understood with an example. It was an honest mistake by left loyalists. Say you were reading a mystery novel. Instead of reading it from the beginning, you start the book in the middle. Since the first half of the book usually develops the characters and the plot, starting in the middle can cause the story to appear to take a different direction, in terms of the conclusion you will draw.
For example, say the novel is about a retired spy enjoying retirement with his wife at their exotic home. One day a former adversary, attacks them and kills his wife. This is the first chapter where the plot begins.
Say you started the novel in the middle, and do not know the story line defined by the first chapter. Instead in the middle chapter, that you start, the hero is breaking into a mansion and stealing a brief case. One does not know he is the hero but rather it is reasonable to assume he is a thief or the villain. You lack the front end context to know for sure. Instead you will have infer, based only on someone break in and stealing. This usually means thief.
This is why Barr is about to write the first half of the mystery novel. The rough draft is already done, thanks to people like Senator Nunes and investigative reporters like Solomon and McCarthy. Barr will add more facts and then turn this rough draft, into a finished first half of the book. Once the novel is reread, from start to finish, the inference and conclusions will be totally different. The Democrat leadership is fighting the writing of the first chapters, since they know their goose will be cooked. On the other hand, the Democrat, rank and file, will not be able to ignore their own common sense when they read the fill novel. They could only ignore the truth, when they were told to start the book in the middle and forget about the beginning. The left was played by their own leaders.
