Many modern day immigrants are not interested in assimilating or becomeing Americans. Rather they view themselves as colonizers much like the white man was when he came upon these shores and found native Americans. Unlike earlier immigrants for whom coming to America was a one way trip and assimilation not a matter of choice. Today's modern immigrant is simply a cheap plane ticket away from returning to his homeland. From California to the Eastern Shore in 100 years we will be in the same position as the Indians were. It's also simple demographics, they reproduce faster than we do. Americans by and large have a lower reproductive rate than 2.3 children per couple which is what is necessary to merely replace yourself.
You have power hungry, vote hogging democrats and greedy cheap labor big business republicans to thank for our current predicament.
How true, how sad, we're doomed if it's not stopped soon.