When detained at a border, a person is not considered inside the US.
>Theoretically, the constitution applies to all people in the united states jurisdiction
That is absolutely not correct. When I enter the USA on the visa waiver program, it very, very clearly says I have no rights while in the USA. No right to a lawyer, no right to appeal, no right to anything. I must sign that to be allowed in.
No, it does not.
I've traveled to the US on the visa waiver program around 20 times or so, and your claim sounded bizarre, so I actually checked the form to see whether I could truly have misremembered it that badly.
The visa waiver - form I-94W contains no language even remotely as extreme as what you portray it as.
It does contain a waiver of rights that states that you waive any right to appeal or review a US CBP officials determination of whether or not to admit you, or to contest deportation other than on grounds of a request for asylum.
In other words, you only waive rights related to preventing them from refusing you entry and sending you back. Once you're in, you're still subject to most of the the same protections.
http://www.slate.com/articles/news_and_politics/explainer/20...
If what you said is true and they made you sign that form it doesn't matter because the Constitution is still paramount and trumps your signature.