this resembles the situation when a police officer arrests a US citizen. they do that thousands of times a day in the US without first determining innocence or guilt. it's just the first step. and US citizens are generally required to cooperate with law enforcement officer directives. the fact that police have certain, constitutionally limited powers doesn't mean the system has abandoned "innocent until proven guilty."
Here student were already pronounced guilty and forcibly send back on return flight.
> this resembles the situation when a police officer arrests a US citizen.
Its not the same.
When a police officer arrests a US citizen, they need to grant him rights and access to lawyer. If they want to take away that right, they need to have a strong reason and apply patriot act or some specific law. If there is a wrong application of law the police officer and department can be sued for wrongful arrest.
Here the punishment has already been meted out by sending them back forcibly, without any due process, but based on border agents discretion.