One of the issues I have with immigration into the United States has to do with assimilation of the immigrants. Previous immigrants to the United States have been assimilated. But there is some indication that recent immigrants such as illegal aliens from South of the border do not want to be assimilated. Another group that clearly want our society to change to accommodate them are the Muslims. Recently the Turkish Prime Minister Erdogan made a speech to Turks in Germany in which he said that Turks should resist assimilation:

http://www.expatica.com/de/articles/news/Erdogan-cheered-by-16_000-Turks-in-Cologne-.html

Erdogan also recently made in speech in which he said there is no such thing as "moderate" Islam. They are all radical, all have a desire to subjugate non-believers.