The percentage of immigrants (including those unlawfully present) in the United states has been creeping upward for years. At 12.6 percent, it is now higher than at any point since the mid1920s.
    We are not about to go back to the days when Congress openly worried about inferior races polluting America’s bloodstream. But once again we are wondering whether we have too many of the wrong sort newcomers. Their loudest critics argue that the new wave of immigrants cannot, and indeed do not want to, fit in as previous generations did.
    We now know that these racist views were wrong. In time, Italians, Romanians and members of other so-called inferior races became exemplary Americans and contributed greatly, in ways too numerous to detail, to the building of this magnificent nation. There is no reason why these new immigrants should not have the same success.
    Although children of Mexican immigrants do better, in terms of educational and professional attainment, than their parents UCLA sociologist Edward Telles has found that the gains don’t continue. Indeed, the fouth generation is marginally worse off than the third James Jackson, of the University of Michigan, has found a similar trend among black Caribbean immigrants, Tells fears that Mexican-Americans may be fated to follow in the footsteps of American blacks-that large parts of the community may become mired（陷入）in a seemingly  permanent state of poverty and Underachievement. Like African-Americans, Mexican-Americans are increasingly relegated to (降入)segregated, substandard schools, and their dropout rate is the highest for any  ethnic group in the country.
    We have learned much about the foolish idea of excluding people on the presumption of the ethnic/racial inferiority. But what we have not yet learned is how to make the process of Americanization work for all. I am not talking about requiring people to learn English or to adopt American ways; those things happen pretty much on their own, but as arguments about immigration hear up the campaign trail, we also ought to ask some broader question about assimilation, about how to ensure that people , once outsiders , don’t forever remain marginalized within these shores.
    That is a much larger question than what should happen with undocumented workers, or how best to secure the border, and it is one that affects not only newcomers but groups that have been here for generations. It will have more impact on our future than where we decide to set the admissions bar for the latest ware of would-be Americans. And it would be nice if we finally got the answer right.