I'm not a lawyer, so I could be completely off base here.  During the last United States Civil War, Abraham Lincoln responded to states seceding by taking temporary extra-constitutional legal actions through the United States Military to restore the Union.  Among those executive actions was the suspension of the writ of habeas corpus.  The Civil War was a long, arduous process killing 2% of the US population at that time.  President Trump IS the Commander in Chief.  He has created specific Executive Orders that DOES grant "legal authority".  As such, I respectfully disagree with your first sentence assertion.  It will be interesting to see how this plays out.  WWG1WGA!  MAGA!  KAG!  Qbaby.