Glazer, Nathan. "Immigration and the American future." The Public Interest 118 (1995): 45-60.
Excerpt: The discussion of immigration and its impact on American society should be based on facts, on meaningful projections, and on a reasoned discussion of impacts in various areas. The area in which we have the greatest capacity to determine impact is that of demography, though, even here, there are arguments about how good our numbers are. Nevertheless, it seems to be the case that immigrants are contributing about 40 percent of our recent and current population growth.
National Affairs [pdf]