After immigrants are detained by ICE, there are probably records somewhere of who has an attorney, and who is calling family members or an attorney.
For the immigrants who aren't calling any family or lawyers, the poorest of the poor, people with little to no connection to anyone, who may not even say which country they are from, if the administration were actually trying to kill as many disconnected immigrants as possible in secret, would society know?
For example, if the administration was composed of all types of conservative people, but 30 percent were secretly Nazis or wanted racial genocide, could there be a campaign to not just remove, but kill, immigrants, and the public doesn't find out?
Personally, I think the Constitution as we know it is starting to resemble the Articles of Confederation: not fit for purpose.
It WAS an useful document, but we don't have enough people upholding it, and the overall design of the thing is filled with poison pills to democracy. The 13th Amendment's slave labor exception, electoral college, the lack of ranked-choice voting, not considering one's body and devices to be 'effects' for warrant purposes, and so forth.
That is one of the reasons why I favor preparations for a civil war, because a true successor to America would need a fresh document to light the path towards a better future. It would be a painful thing, but I don't think we have the luxury of a peaceful reformation anymore.
Of course, I would like to be wrong. But it ain't prudent to believe that the Donorcrats and Turdpublicans would have a revelation and fix themselves.