These moral equivalence arguments are futile.
I addressed the issue, not only that, the concern about the 'moral universality' of the border laws isn't very relevant.
We put people in prison for 10 years for stealing cars, and there is no 'universal moral agreement' on the issue.
Migrants are not even being held against their will - they can leave in about 72 hours by filing paperwork. They have knowingly entered the country illegally, and are detained. They can go home essentially when they please.
If families were required to 'wait the Holiday Inn' until their hearing (which I think should be the case, no need to hold them in detention), I suggest few would be concerned, so what matters is not so much the issue of detention, but the conditions. I think that most people would probably agree that conditions should be reasonable but that's an operational issue.
But it's besides the point: the US has borders, and just like any for other nation, those borders have to be respected legally by some means.
But this is a giant distraction from the fact that:
China is arbitrarily putting it's own citizens in totalitarian concentration camp conditions due to their ethnicity.
The 'corollary' would be Trump putting 100 000 Latino American citizens in concentration camps purely due to their ethnicity, with no legal recourse, removed from any communication with their families, their every move, thought, action suppressed as they go through intense 'indoctrination training' daily, for years at a time.
It's unthinkable.
But it doesn't stop there:
China spies and censors each and every citizen, kidnapping students, academics - anyone - who speaks out too vociferously against the regime. They rigorously control all established media to enforce propagandistic measures, and censor or suppress anyone who acts against that system. China does not allow citizens to access information outside the country. They've created a giant, dystopian suppression machine.
The corollary would be Trump closing down CNN, NBC, CBS, then taking governmental control of Fox news, and legally requiring Fox to tout his agenda every day. Trump would then mandate Facebook to censor anyone who speaks out against Trump or the GOP / Government. Trump would insert a team of 'GOP agents' within Facebook to ensure absolute compliance. Any FB user who 'talks funny' would be flagged for future reference (i.e. maybe just a little visit from the local cops will suffice to get them to shut up).
Protests would be met with bullets, all media completely suppressed, no legal action or recourse would be possible. To merely mention the issue could land you in jail.
Of course in this scenario, Trump also has absolute power, does not need to be elected, directly controls the Fed/Monetary System, directly controls all major financial institutions, can amend the constitution essentially at will, has no need for any kind of judicial system which would of course be politically controlled, so he could put his enemies (or whoever) in jail whenever he wants, for whatever reason.
Of course he could direct Verizon, Google, AT&T, Stripe, Amazon to provide him with transactional data for anyone, anywhere on earth at anytime, for any reason.
And all of that is only scratching the surface!
So start justifying that list of transgressions, and when we get down to things like 'North Koreans fleeing to Chine held in less than optimal conditions' ... then we're having a discussion.