The problem is rather universal among humans. Most of us learn one language well. Some can learn to speak two or more readily, but they are a distinct minority. Some of us are gifted in being able to dicipher what folks with poor English language skills are saying.
The Hispanic people moving up from Latin America face a double-barreled problem. First off, they didn't receive a good education in Spanish. Secondly, their English vocabulary will, in just a few years experience, become far larger than their Spanish vocabulary. In numerous communities this is driving their creation of a creole language we call Spanglish.
That's why I love Reggaeton music from Puerto Rico ~ good beat, quite danceable, and yet, I can understand what they're saying because they use my words!
I like that music, too. I wonder, do you feel this whole mess about being "overrun" by a population that "won't" assimilate is a little rediculous? I do. Maybe this is because I remember my grandparents and how they longed for the old country...I remember hearing how much better things were over there...then when I finally went (and I did love it) within two weeks I was ready to come home (and eat a freaking cheeseburger).
So very true.
But the problem is that first generation immigrants of the Spanish variety have largely negelected to direct their children to learn English as their primary language.
Most people understand that new arrivals of any variety have a difficult time learning Enlish.....Its the history of our country But the newly arrived Mexicans and other Spanish speaking peoples flooding America now are the very first major group of immigrants to work diligently to insure that their children do not make English their prime language.
That is an undeniable fact and a terrible pity for their own children.