quite frankly when you have huge numbers of immigrants who have no desire to assimilate into your society, you weaken the fabric of the country. we are facing the same thing here where the flood gates were left open, primarily on our southern border and it has weakened our nation financially, morally, physically (most have never has immunizations of any sort) and about any other way it can be corrupted.
We allow 2 million - yes, 2 million in LEGALLY per year... that's far more than reasonable. We now have roughly 15% of the population of mexico living here ILLEGALLY and with them, they bring crime, poverty and disease. We have had an administration refuse to enforce our own laws, and those running for the white house in november have been right in line with this lawlessness. We have a few of our border patrol agents who are now political prisoners who are in jail for enforcing our laws and shooting an armed drug smuggler in the rear-end!
Unregulated immigration cannot work - ever - particularly when the immigrants do not wish to assimilate or wish to do harm to your country and government.