Words of wisdom from Steven Taylor:
Under the German Nationality Law of 1913 (which was in place until the Germany Nationality Act of 2000) the principle for citizenship was one of jus sanguinis (i.e., right of blood) rather than jus soli (i.e., the right of the soil). As such, the children of immigrants had a very difficult time becoming citizens of Germany.
So let's consider the following scenario: you invite a large number of persons to come to your country to work, often doing menial labor. You tell them, however, that they can never be truly part of you country. And then you are surprised when they aren't integrated into your society? Why act like a German if you are never going to be allowed to be one?
Proponents of amending the 14th Amendment take heed, as this is what you are asking for.