Families aren't being torn apart.
If you turn yourself into border patrol, the normal procedure is to be held in custody while awaiting a court date for your asylum hearing. This was considered inhumane to do to minors.
It was then considered inhumane to separate minors from their parents.
So now, if you turn yourself in, you are told you have a court date and then released. And it's very easy to just then disappear into the interior. There are even coyotes who are having minors going back and forth, posing as the children of new illegal immigrants to ferry them through. And then there are the human traffickers.
It's a huge mess and it's made worse because of congressional deadlock, with Democrats wanting to make the situation as awful as possible because that make's Trump look bad.
Superman wouldn't round up illegal immigrants, but he would be pissed at them playing politics with people's lives.
Trump has two main modes. Make America Great Again and Fuck You Buddy. MAGA is just "I'm #1, #1 country, we're awesome." and FYB is "Call me a racist? Fuck you, you have a tiny dick.", punching back at his critics. And since everyone is criticizing him, he does that a lot.
A lot of "stirring up" is generated by the media, such as the "immigrants are animals" hoopla.https://money.cnn.com/2018/05/17/media/media-trump-animals-immigrants/index.html