When some of the significant FISA stuff comes out--and the public realizes that the head of the SC, Roberts, who oversees the FISC court was authorizing/sanctioning unauthorized surveillance on a candidate and our President, then the courts are going to lose some legitimacy as well.  That's something I forgot to consider.  Technically that doesn't NEED to happen for military tribunals to be legitimate for treason, but from a PR standpoint you're correct.  Good point!  and there is, if memory serves, some historical precedents to support this idea.  We need to start researching and publishing past cases of this kind of justice.