Crossing the border is illegal, bringing children with you is classified as human smuggling and is a crime. American citizens who commit crimes are separated from their children all the time.
Would be interested to see what if any "child dumping" occurs in catch and release scenarios, and of course catch and release often results in "lost child" situations that LibBots meltdown about as well.
But logic and the LibBot are mutually exclusive.
Catch and release also encourages illegal immigration.
But what nation needs a controlled border anyway?