Unfortunately authority 'given' to CBP at the actual border (for crossers) significantly exceeds that of the 100 mile zone. They can basically detain you indefinitely without charging you with a crime and meanwhile strip search you, finger print you, toss you in a cell, etc.
The constitution doesn't apply at the border. Maybe in theory it does, but in reality it doesn't. CBP Officers specifically told me "I consent to whatever happens afterwards when I cross the border."
[ Also been told once, me a US citizen with a passport, that they had decided not to let me in my own country. Was not let through until an HSI detective came to "make sure I wasn't ISIS." ]
You get no attorney. You can't contact anyone. You can't touch your phone, if you have one. You can be tossed in custody without any oversight, and without being mirandarized. I have been booked, finger printed, tossed in a cell as a US citizen who provided a legal passport and violated no laws. You can be tossed in a van, cuffed and shackled and driven wherever they like, including hospitals where they will try to convince doctors to anal probe you (this is a real example from my personal experience).
I've studied the court cases involving US citizens, including a woman who had her orifices brutally penetrated until they were raw by a doctor[0]. THe federal docket shows no real result, and that the CBP investigated themselves and determined they did nothing wrong.
In the end the courts don't give a fuck, and most Americans don't even have a passport. I'm quite sure a good 10% of Americans would go along with a proposal that said "We should allow border patrol to shoot any suspicious persons at our borders." Border and immigration are notoriously dystopian arms of the government, because citizens either have bigger concerns or just don't give a shit what happens there.
If you contact a lawyer regarding border abuse, they will basically refer you to the (swamped) ACLU, because they know it's a waste of their time to even try.
I'm sorry that all happened to you, that sounds really bad. I'm not doubting your experience. However I think it's important for Americans in particular to maintain the distinction between "the Constitution applies and border police are acting illegally" and "the Constitution literally has no force in these situations" when discussing these problems in forums like this one. A lot of the recent creeping fascism involves the fascists treating the law as if it didn't exist, but when actually called on it they back off.
Of course as a practical matter anyone crossing a U.S. border should understand the risk of arbitrary violence, deportation, detention, or having all your stuff taken.
I feel it. My only point was that "the Constitution applies and border police are acting illegally" and "the Constitution literally has no force in these situations" are both simultaneously true.
Honestly illegal border crossers are the only ones who maintain their constitutional rights, because once they've crossed it is impossible to prove it unless someone actually saw them do it. I've read border patrol officers comment that if a US citizen is found at the border there's basically not much they can do unless someone caught them crossing in the act.
I'm not sure what you mean by illegal border crossers. Do you mean U.S. citizens who sneak back into the U.S.? It actually never occurred to me that was punishable (instead of just a bad idea) but it looks like it is. I learned something new.
By the way, if you haven't seen it, you might like this old favorite of mine: "Born in East L.A." with Cheech and Chong, parodying Bruce Springsteen's "Born in the U.S.A.": https://www.youtube.com/watch?v=sFUFw1GH6ic. I was going to it's funny but in light of this discussion, maybe not. Not as funny, anyway.
