I'm waiting for 'jcranmer to respond to this, because it was a response to this claim years ago that started me following him, but, no: the "100 miles from the border constitution-free zone" thing is a myth.
I wasn't planning on responding to this, because the sibling comment already points out that the ACLU's own explainer page is walking back its original description of it as the "Constitution-free zone".
Although while I'm here, I will note that they still don't discuss the fact that--as far as I can tell--all the regulations and laws means the 100 miles start not from the water's edge, but from the international boundary, which is 12 miles out to sea. And which also means Chicago is not in the 100 mile border zone, since the actual Canadian border is on the side of Michigan, well over 100 miles away.
