That is also part of the problem. Many of these people are not adults, but kids that their parents hired coyotes to smuggle across the border, because they know that the US will take better care of them. And these are the worst things for the US. Because hey boo hoo hoo, they are kids, we can't send them back. And if we keep them here, until they turn 18, we the taxpayers have to pay everything for them, since their parents are no where to be found.
At least illegals that are families, you can count on some tax revenue coming in. Whether it be sales, possibly even income or property taxes. But these abandoned kids are nothing but a money pit.