…and I think the reply answers the question (although I find the answer a horrifying thought as well).
My point is - I don’t think the person replying to you was endorsing the idea, just giving a plausible explanation for why there’s not an immediate uproar: perhaps some folks in government are actually okay with that. :(
I'm not endorsing the behavior, but think like a politician for a moment. Someone comes in and takes care of a legal and ethical mess. All you have to do is get out of the way and not interfere. Not only do you not get smeared with this mess - you even get to be a knight in shining armor who'll replace the bad guy later. And your problem stays gone. Seems like a no-brainer.
Not to sound insensitive, but if they are only holding noncitizen criminal deportees awaiting transport back to their home country and they are able to do that cheaper than we can in the US…I am have a tough time seeing a negative with this.