I'm with kgsbca & markci here; this isn't about legalities or the Constitution at all.  Ackerman can write this because many believe Bush's cronies would stoop to anything, including a military coup with fig-leaves over ykw.  But if that leaf is a secret EO, how is it any better than one issued "a few hours earlier" when "we became aware of his threat."   Binding on the Executive Branch, maybe, and only.

If such legal ignorance could prevail in DC, we've got bigger problems.

OC I'm sure AG Mukasey is the Man to defend Anything.  (BTW, fellow Editor of Yale Law Journal w/ Ackerman, c/ '67; you don't suppose they think alike?)