Good thing this scenario is entirely fictional. Even if it weren't completely made up, though, you'd still be ethically obligated to assess immigrants as individuals and not simply guilty by association, except perhaps under the most dire wartime circumstances.

You'd also be legally obligated, but to be lawful is not always the same thing as being ethical nor moral.

It would be challenging, I admit, considering the country will have doubled in size with half of them being infants that naturally don't speak English, or any language for that matter.

We really should close that loophole, though. And it definitely is a loophole and not the explicit intention of a constitutional amendment. An oversight to be sure.