The U.S. Constitution is clear & direct in its definition of "treason" -- waging war against the USA or providing aid & comfort to our enemy.
So Lincoln's release of Ohio Congressman Vallanigham to Confederates only demonstrates that Lincoln had a great sense of humor!
As for Dred Scott's Chief Justice crazy Roger Taney, well... not clear if by 1861 he was even dangerous enough to be arrested for giving "said & comfort" to Confederates.
I don't recall hearing of any convictions for "Treason." Perhaps you could remind me of when those happened?
So Lincoln's release of Ohio Congressman Vallanigham to Confederates only demonstrates that Lincoln had a great sense of humor!
It demonstrates he had no qualms about doing whatever he thought he could get away with and the Constitutional be D@mned.
So you are claiming Vallanigham committed treason by criticizing a President who started a war that killed more people in single battles than the entire casualties of all previous wars?
Doesn't the constitution require at least two witnesses to convict someone of treason? And I must have missed the part where Military Tribunals (Military is under the direct command of the President) were part of "due process."