A couple of decades ago I read articles that if we spent an extra five billion dollars we can harden electrical grids against an EMP attack. I do not know the cost today. But if the factories can still be open after an attack and retooled we can produce parts at least to make parts destroyed under an EMP attack to work again.
Recovery from a hurricane strike soaks up a lot of manufacturing resources just in replacing transformers.
Now figure that every piece of construction equipment is microprocessor controlled. Every aircraft, every locomotive, every towboat, every 18-wheeler. All would be inoperable until the electronics were replaced. Every railway and air traffic control center...dead. Every internet hub, every data center, every personal device...all useless junk.
The factories you think can be retooled? Nope. All CNC machines would be trashed. No way to build the microprocessors that run everydamnthing.
It's incredibly short-sighted to think our technological civilization can simply recover from an EMP. You'll be heating your house with cow dung and telling your kids stories about when food was easily and readily available.
Kudos to President Trump for having more foresight than his predecessors.