The legislation I linked to suspends all constitutionally-guaranteed rights "at" the border (ie within 100 miles of a border crossing, including any airports with international flights) if you are not an American citizen. The suspension of constitutional rights has been tried and upheld by a number of SCOTUS cases.

There is no international body regulating any other kind of right, despite the well-meaning intention of a number of organizations.

If you are not an American citizen you are still a citizen of some other country, which has its own obligations before its citizens to uphold their human rights, even when they cross someone other's border.

This may end up ugly for the USA if they try to abuse that decision. Not every country in this world is Mexico.

They abuse it routinely. Almost any Canadian who crosses regularly has seen it or experienced it. Especially since 9/11. It's just part of life being next to an aggressive large imperial power.

>which has its own obligations before its citizens to uphold their human rights

So you want the country the person is traveling from to impose their Will on the country they are traveling to?

Yes and it will definitely happen. Their ambassador sending notes to your state department and then starting to reconsider bilateral agreements.

Happens all the time.