You should read Phyllis Schlaly's report, How Mass (Legal) Immigration Dooms a Conservative Republican Party
Milton Friedman said, “You cannot simultaneously have free immigration and a welfare state.” We have both.
As a side note, I would add that immigrants need to assimiliate into the American culture and learn the English language. Like most people back in the day, when my Grandfather came over from Europe, he wanted to be an American and part of the American community/culture. He learned English (on his own), was very proud to become a citizen, worked hard, raised a family, etc. One of my big gripes is that you see pictures (albeit mostly Mexicans) that don’t want to assimilate - - they are illegals that march down the street caring Mexican flags and flipping us off.
It is a function of numbers. We have a hard time assimilating these huge numbers. We have 45 million foreign born in this country. In 1970, one in 21 was foreign born; today it is one in 8, the highest in 90 years; and within a decade it will be one in 7, the highest in our history. We have just had the two highest decades of immigration in our history--over 25 million have entered in the 20 years ending in 2010. And the Gang of 8 bill wants to add another 30 million IN A DECADE.
Consider this: There are 10.4 million students from immigrant households in public schools, accounting for one in five public school students. Of these students, 78 percent speak a language other than English at home. Overall, one in four public school students now speaks a language other than English at home.