Action "outside" and "against" the Constitution is never constitutional: thus the Supreme Court, in opinions rendered after the Civil War and reaffirmed recently in Hamdi vs. Rumsfeld , has held that the Constitution is in operation at all times, and that no "war exception" exists to the requirements of the oath to uphold and defend it that bind every state and national officeholder.
We are talking about AEI here...any non-praise of the 16th president is swept under the rug. Forget Milligan, the new (and old it seems) Republican mantra is to keep doing something until someone tells you to stop. Then feign ignorance as if you didn't really know it was wrong to do it.