Many of those "parents" don't want their children back, simply because they were not their children in the first place! Pres Trump tried to explain to Joe and his thick headed crowd, how coyotes were using the leaky border to sneak in criminals by allowing them to use other people's children as a cover for their nefarious activity.
Apparently the real parents were so desperate to have their children escape 'socialism', that they surrendered to the coyotes..
Sadly however, some of Joe's brilliant backers thought our president was talking about the mouse-catching kind of coyote !