I don't think we should have this conversation without specifying that the thing most Libs (Lubes, Dems, whatever) were upset about under the Trump administration border policies was the forcible separation of children form their parents upon apprehension, not the detainment. What the Biden Admin continues to struggle with currently is kids trying to cross the border unaccompanied by their parents or guardians, so they are detaining them until they can figure out what to do. Orangeman bad because he intentionally created unaccompanied minors and violated human rights, Bidenman not as bad because he didn't create the problem but he is struggling to find a solution.
Yes the kids in cages pictures was taken under Obama and created hubbub under Trump years later. HIPOCRACY!...or whatever...that doesn't change the fact that Trump intentionally, seriously exacerbated a problem in a really dickish way.