We have accepted this principle for years.
But what you do when you use it as an argument in these times is ignore the numbers. Latino numbers dwarf all other immigration legal ... and illegal ... over the last 150 years combined. It's the numbers that are breaking the state budgets, as they struggle to serve all these new people who although they are here illegally, still soak up services as they get organized and get to work. Mexico's population is exploding geometrically, and if they walk north unchecked, in 100 years there will not be an English-speaking United States. it won't be a solvent US either!
And Mexico is just one country in Latin America. The Mexicans have been joined Central Americans, and more ominously by South Americans like Bolivians, Peruvians, and others whose Third World countries are bursting at the seams with 10s of millions who cannot be fed at home.
These huge numbers themselves are dwarfed by the potential influx from Asia, where Latin America's Millions are matched by Billions.
The more or less orderly immigration of more or less culturally adaptable Europeans in large but manageable numbers is not what we are talking about. There was never a danger of the US becoming a Polish-speaking country!
If all Latino immigration were to be stopped tomorrow, the US would still become a predominantly Latino country in 100 years or so, but hopefully still an English-speaking one. We do need orderly immigration from around the world, but on a numerically manageable scale, without allowing any one of the many monocultures that could, take us over. For example, Latinos need to be Americanized. One look at Mexico, or Honduras will tell you we don't want to be Latino-ized.
So, now would be an excellent time to get our borders under control. We have the laws. Our leaders haven't shown the will. The Border Patrol and the INS should be made bigger than the Armed Forces. The numbers we have to control for admission are that large.
Thanks for the post. :)