This is one of the many problems with America being a huge melting pot of different cultures. You lose the fundamental values our founding fathers had. Because the more you let in different types of people with different cultures and backgrounds, the more they want to change America to fit their desires.
And in regards to the article link above, America has gotten so soft on the issue of letting others in, we are now seeing the enemy show up on our own soil. Much of this is the fault of Obama and like minded liberals. If it were up to Obama we'd have no border at all as he is a one world global government elitist.