TWIC card already in use for anyone connected to transportation industry. If you haul,load,unload,or just push a broom near any load from a port then you must have TWIC. I had to get one just to pull loads out of a port. Didnt really want it but only had to be fingerprinted so figured they already got those so I wasnt losing anything more.
Really think this National ID is a whole other much bigger beast though. They say if you dont have it you cant work. So whats to stop them from later saying you gotta have it to buy food etc?