When you start applauding KKK members, then you'll see why many of us who are pro-immigration ultimately end up in discussions of racism. It is the ONLY factor that ultimately separates your arguments from every other logical argument about immigration, namely that there was MORE immigration, and HIGHER RATES of immigration per capita in MANY earlier years, including the ENTIRE DECADE from 1900-1910; that MANY other groups, including GERMANS were far less assimilated than you think Hispanics are (there were 27 DAILY German newspapers in 1910); that these groups were viewed as a direct national security threat, as opposed to some nebulous concerns over "Aztlan" or whatever.
So when this comes up again, all you need say is, "I stand with Klansman Byrd."