Illegal aliens contribute big bucks to Social Security, but cannot draw. They also pay taxes, but cannot file tax returns, therefore they don't get back any overage they may be paying to Uncle Sam. The New York Times > Business > Illegal Immigrants Are Bolstering Social Security With Billions This is just one source. I have seen that number go as high as 20 Billion. Basically what we have here in the illegal aliens is an under class that is required to pay into the system, but can get nothing back out of it in terms of Social Security or tax returns. AND if they are working and bringing home the bacon, the welfare argument fails.