There are many thoughtful and intelligent people who support comprehensive immigration reform, and who believe that welcoming more low-skilled workers at a time when the American economy subjects such workers to intense wage pressure is a wise course of action. David Brooks is one of them. He has consistently made a humane, decent, optimistic case for a more inclusive immigration policy, and our public conversation has been greatly enriched as a result. Nevertheless, I’ve come to see the immigration question quite differently.

For a variety of reasons, the United States has a large population of people who are not just poor, but who are the children and grandchildren of poor people, and who are isolated from our society’s economic and cultural mainstream. One of the great dangers we face is that while less-skilled immigrants are upwardly mobile, in that they generally lead better lives in the U.S. than in their native countries, their children and grandchildren are in many cases experiencing “downward assimilation.” That is, they find themselves stuck on the bottom rungs of the economic ladder, suffering from many of the same problems that plague other very poor Americans — they are being raised in unstable families, they are victimized by criminals at high rates, and they have far less faith in American institutions than their immigrant forebears did. This is not because these men and women are any less admirable than more affluent, more established Americans. It just so happens that there is only so much that government can do to ensure that the children of parents with low levels of literacy and numeracy will flourish in a society that prizes skills and social capital. Congress can increase transfers, certainly. But it can’t repair frayed social bonds.