Earlier quoted context omitted.
I think you're getting it very wrong; this isn't about people saying "let's just allow illegal immigrants the full rights of legal immigrants". There are some people saying that, but they're a small minority. This is about saying "some people have come here illegally. let's not psychologically torture their children for it" You can be for legal migration and the humane treatment of people at the same time.
What’s the alternative? Anyone else that commits a crime and is imprisoned is separated from their family and children. Why should illegal immigrants get a pass?
Not every crime is prosecuted and not every conviction means prison. Why should immigration be different?
(And that's before we even get to the question of reports where people presenting themselves for asylum -- a legal process -- have been treated as if they're breaking the law. Or ways in which recent policy seems to have been tweaked to otherwise gum up legal immigration avenues.)