As I understand it, separating children from parents isn't some sort of arbitrary punishment, it's literally the only way that immigration laws can be enforced when adults are traveling with children. This is because of court decisions which say children can't be detained more than 20 days. The alternative is to just release the parents and children and tell them to show up for their court date, which they usually don't do. So if you're saying we shouldn't separate children from parents, then you're for defacto open borders.

The humanitarian crisis at the border is caused by lots of people showing up at the border, right? It seems like the only way to stop the crisis then is to get people to stop showing up at the border, and the only way to do that is to enforce immigration laws. Is there another answer?