People so driven by a sense of nationalism that they will tolerate anything to preserve their "heritage".
Thats the best I can do.
Nationalism is a good thing, but in the wrong hands or taken too far, it spells doom for a nation. The Germans and the Japanese learned that lesson the hard way, and it cost the world millions of deaths. My father spent six months in a German POW camp watching it, and his own German mother refused to believe what he told her.
I am proud to be an American, and I welcome immigrants that are willing to become Americans. They have to learn english to prove to me they are serious.
A lot of people underestimate the power of our country and the effect on the people that come here. Who wants to be a Mexican (or anything else) when you could be an American?
Punishing people for chasing a dream is hard for me to do.
Who's doing this? We are trying to punish people for breaking our laws. Anarchy by any measure diminishes our country. Illegals are not just "chasing a dream" they are breaking laws on a daily basis.
The Japanese have a relatively homogenous poipulation. The problem there was hostile imperialism, not a rational desire to keep ones land and culture.