As best I can see, Flynn was dirty. The Turkey connection is new news. It is because of this Turkey situation that he was pursued so aggressively about lying to the FBI. They prosecuted what they could — the Turkey matter being far more difficult.
He is going down because he should go down.
His part in arguing that a cleric should be deported doesn’t sound like treason to me. He was registered. How could he have been trying to hide this from POTUS when it was out in the open?
Old news. Was brought up in spring 2017 at the WSJ and other sources.