You must realize that the case for the South is so very bad, that these guys latch on to any little thing which even remotely bolsters their position. That's why a letter from a Cardinal becomes diplomatic recogntion by the the Vatican, and not passing a bill Lincoln may or may not have had anything to do with, becomes a condemnation of his war powers.
Such is the confederate fantasy world.
Lincoln took the actions needed to stop the insurrection and win the war; a building consensus in the Congress and among the loyal people supported him; and the confederacy died an ignominious death.