> Maybe not guaranteed, but still certainly creates a certain problem of deporting the parents when they can't the child, not to mention general sympathy of splitting families and such, and no one wants to be on the news for that.

Although they can't deport the child, most parents would still bring the child with them if they're being deported in the interest of being able to continue to act as the child's parents, unless the government makes no effort to enable that kind of family unity to be possible during the deportation process, or unless there's a trusted close relative in the US who can give the child a sufficiently better life apart from their parents than whatever mess the parents might be returning to in their country of origin to outweigh the family separation.

I'd love to see stats if you have them regarding cases where a deportation would leave a US citizen kid with no parents who continue to reside in the US and where the government offers to let the parents choose to bring their US citizen kids with them during the deportation at government expense. (Parents in this situation often couldn't afford to reimburse the government for such costs.) Family law generally allows parents to bring their kids with them (below age 18) regardless of the kids' citizenship, at least if no parent is arguing in court for a different outcome.

My expectation is that most parents given that option would choose to keep their kids with them, and that any resulting family separation which wouldn't already exist without a US citizen kid is simply because the government isn't prioritizing family unity in this context.