States of Emergency

Trump made news in the last few days by threatening to declare a national emergency to allow him to have his wall built along the Mexican border without appropriations for it from congress.  Some said he lacked the authority to do it, though he probably  does.  The National Emergencies Act is pretty clear.

To me the more important question is why we have such a law on the books. It make sense to have laws authorizing  a president to take otherwise prohibited actions in response to specific threats or sets of threats. Examples might  include some powers that would be needed after  a powerful sneak attack (nuclear or otherwise) on the United States, the authority to enforce quarantines during dangerous epidemics,   and the power  to requisition uncontracted civilian aircraft to move forces quickly  to actual or potential foreign battlefields.  However it makes no sense to give a president wide and dangerous powers,  including declaring martial law and seizing property,  in whatever he or she chooses to call a national emergency. (Emergencies can be cancelled by the congress, but a president who  has  either  the support of the house or enough votes to block action in the  senate is home free for at least a year.)  The congress should fix that but probably won’t.