If this is truly civil with no burden of proof on the government then you just poofed away the rights of every citizen with that legal opinion. You can simply assert they aren't citizens, non citizens aren't promised any contact with the outside world while detained to acquire proof of citizenship, deport.

With that reasoning there is no purpose for most of our laws or legal opinions, the government is free to do anything they want to any person at any time.

If you support that bullshit you are truly a authoritarian asswipe.