These people may not have the legal right to defend themselves, verbally or physically. It is entirely possible that the current SCOTUS would deny them the right to free speech; the right to bear arms; the right to be secure against unreasonable search and seizure; the right not to incriminate themselves; the rights to speedy and public trial, an impartial jury, and legal counsel; or the protection from excessive bail and cruel or unusual punishment.
This is how the threatened "mass deportations" are going to happen, and it will be completely legal. Hell, deportations? They could be executed without trial, and that would still be legal.