It's a basic rule of human nature: if you reward bad behavior, you'll get more of it.
That's why pity can't trump common sense regarding thousands of children arriving in our country illegally. If we welcome them with benefits of this compassionate society, we'll draw millions more expecting similar treatment. It may be complicated and costly, but newly-arriving illegals must be quickly repatriated to their countries of origin.
And what about the undocumented millions who've worked here for years? Wouldn't a path to legal status reward their bad behavior? Actually, no: immigration reform rewards good behavior—admitting wrong-doing, paying fines and back taxes, mastering English, going through background checks, embracing the rule of law. And after they earn legal status, undocumented workers should get no special route to citizenship—instead, going to the back of the line to pursue the same process as legal new arrivals.