Which is it? Should New Mexico be a part of Mexico, or the United States? Make up your smarmy little mind.
The reason the United States has been a melting pot of cultures such as the world has never seen before is precisely because we all shared a common language. Destroy that, and in a hundred years the US will be more fractured and backward than the Balkans ever thought of being.
I think everything you said is 100% true, except, I don't think it will take a hundred years. I am afraid it will happen much sooner than that.