Second, immigration opponents are trying to restrict assimilation. The evidence about this is clear, too. Current immigrants enter this country because they want to realize the same dreams that inspired past waves. Study after study shows current Hispanic immigrants are picking up English at an impressive clip, roughly as quickly as earlier immigrant groups. They are making steady gains in homeownership rates, job status and social identity. By second generation, according to a Pew Research Center study released earlier this year, 61 percent of immigrants think of themselves as “typical Americans.”

Third, immigration opponents are trying to restrict love affairs. Far from segregating themselves into their own alien subculture, today’s immigrant groups seem eager to marry into mainstream American society. Among all newlyweds in 2010, 9 percent of whites married outside of their racial or ethnic group, as did 17 percent of blacks. But an astonishing 26 percent of Hispanics and 28 percent of Asians married outside their groups. They are blending into America in the most intimate way.

Fourth, immigration opponents are trying to restrict social mobility. Generation after generation, the children of immigrants are gradually better educated and more affluent than their parents.