There are a bunch of X theories about that very thing. The fact that the Flag is the War Flag, Maritime Law and other stuff. Going back to Lincoln IIRC. At some point along the way the Constitution was "temporarily suspended" and never got un-suspended is the short version. If it ever came down to a Nuremberg situation, these would be the "legal" papers that would be presented out of nowhere in defense of all political malfeasance over the decades. This is why "Day of the Rope" has to be true to it's name. Clean slate. Kill all sophists.