Maybe you’ve seen this meme.

The implicit argument is that since a small percentage of refugees may turn out to be dangerous, we should exclude all of them.
But, similarly, a small percent of the native-born children will become murderers, rapists, and other criminals.  Children born to poor families–including the many of the white people who voted for Trump–have an especially high chance. By the logic of the meme above, we should exile those infants, require infanticide, or require their parents to be sterilized. Letting poor people have kids is like eating a handful of the skittles.

Ah, you might say, but native-born children are different–we’re required to treat them better than we treat foreigners.

I won’t argue against that point here (Bas and I take it up in detail in our forthcoming book). But notice: The people who think the meme above is a good argument need to explain why this reasoning doesn’t also call for forced sterilization or exiling certain native-born children. The argument in the meme presupposes, rather than proves, that we can treat foreigners in ways everyone would think are impermissible to treat their co-nationals.