greekdog.. not going to copy the post, but you made some excellent points.
One seems similar to what I have said, specifically that there is a difference between saying "we will allow you to do as you want" and allowing other people to essentially force how you do things. Initially, I made a big distinction between the US and Europe and certainly, there is a difference. However, those who said we have no "base culture" are also incorrect. Even though we try to avoid stereotypes in individual interactions, the truth is that you often tell if someone is born and raised in the US, in Canada or Europe.. and I don't mean just the accents. California and Texas are experiencing something similar to what I hear is happening in Europe (mostly from my relatives in Scandinavia). On the one hand, most people don't really want to say "OUT" -- at least not initially. However, part of what makes people so angry about Mexicans is that they come here and then basically DO turn around and say "you learn MY language.. why should I bother learning yours". (there are plenty of exceptions, but having grown up there, there is a lot of truth to this stereotype) When you add in the numbers and things like dropping job opportunities, problems in schools, etc, etc. -- even the most open minded and liberal person (I use to consider myself in that group, but in this issue, perhaps not) is likely to say "STOP". You don't have the right to change our society overnight! And.. sometimes it seems that is what is happening.
Like you, greekdog, I am the child of an immigrant (though only 1). I grew up attending organizations dedicated to my father's culture, etc. Yet.. even while people wanted to hold onto parts of the culture, they in no way wanted to denigrate the culture of those already here.
The Native Americans are, sadly different. However, even for them I am not sure there is much choice except to find ways to at least partially meld. I DO think we owe them a real obligation to help sustain their culture. We have gained from that association, but have not "returned the favor". We cannot and really should not undo the past, but we can say "OK, because we screwed up so badly our society owes these others something." That topic has come up before and deserves its own discussion, but I wanted to clarify that it is a seperate issue, apart from the more general issues.
Your last point is really key. When I was in school, I can remember hearing about the "American Dream" and the "melting pot". They were all sort of merged as something positive. Yet, the truth is that people came here for many reasons. Some did come to escape persecution and so became even more tied, perhaps to their "base culture".. though in the past, we have heard gratitude in that mix, perhaps because numbers were always limited. Its not that they necessarily want their kids to forget their "home" culture, but they recognize that their children have a new home and simply must adapt.
Far more came purely for economic reasons. A lot of the newer immigrants that are causing issues came here for the "opportunities". They are more mixed. I don't think its cooincidence that the same group that shows the greatest disdain for our system, namely Mexican Americans, are the ones who often came here illegally. (note, I am WELL aware that there are many exceptions to this, but I want to concentrate on those causing the problems). I don't believe, as others have asserted, that they present a real crime problem, other than the new drug-associated issues. However, being illegal, they had no real incentive to "meld". Most fully and completely intended to return. They may have wound up staying, but evne then, it is an uneasy stay. This is a tad ironic, because the answer is to allow legal immigration, but also to limit it. Again, that is yet another tangent. I mention it just to be clear, but its another topic. Anyway, it might not be that the illegal aspect particularly is the main issue there. I might just be sheer numbers. Far more people from Mexico come here than from Europe or other locations.

