It is not an either-or situation. Just because some men don't pay child support, we don't give an amnesty so they never need to anymore, every murderer isn't caught, every speeder isn't ticketed. You can enforce laws without getting 100% They could focus on getting the worst illegals deported --- those committing felony document fraud, those found committing other crimes --- DWI, shoplifting, driving without insurance --- without going door-to-door to try and find every last one of them.
I think we are well beyond that argument when you have millions of illegal aliens.