Except that they wont ever get around to the ID system.
Look at DHSs record in carrying out previous congressional technology mandates of this sort: the "virtual" fence, the "no fly" list, the scanning of incoming freight, the system that allows Border Patrol stations to communicate with each other, access FBI databases and identify criminals, I could go on, but you get my drift. None of it is ever done effectively. They spend billions and it doesnt work.
Those who, quite reasonably, fear this ID plan can take comfort in how extremely unlikely it is to ever be established as advertised. It is just one more lie they are willing to tell in order to get their amnesty plan passed.
It is there..do a search on the net..plenty of info on it.