It was criminal under Obama too. No laws were changed under the Trump admin. People are just unrealistic and delusional about how to manage an immigration system, and certain politicians like to make disingenuous arguments for personal gain.

Most people complaining about family separation don’t even seem to be aware of the fact that it doesn’t apply if you’re a legal asylum seeker. It only applies if you’re caught breaking immigration law with some coyote (many of whom routinely traffic and rape children, or worse).