Another thing that could help this happen is if the anti-Davis forces do something really stupid. I'm not sure how it would work, but my idea was something like this. Let's say Toombs, Stephens, and the other anti-Davis men decide to launch a coup and depose Davis in favor of Stephens. They don't have access to enough militia troops, so they make a deal with the Devil. They make contact with Ulric Dahlgren, and get the plan to kill Davis bumped up a couple months. The plot still fails, and the papers connecting the Union with the conspirators are released. It's extremely unrealistic, but it has to be in this case.