Everyone sez that immigrants help this country, we are a nation of immigrants, etc. One way we can guarantee that every immigrant that is here truly does help us is through taxation. Let's figure out the cost of running America, say 3.6 trillion a year for FY 2012.
Divide that by 300 million people, that's 12000 dollars per year per person. (Basically, we as citizens average out to that, or at least we should)
So, each immigrant who comes here and "helps us" should pay us $231 a week in taxes for us to break even, just on the Federal costs of running this country. Presumably, local taxes like sales tax, property taxes, etc get paid through rentals of apartments, purchases at Wal Mart, etc. Roads are paid for with gas taxes, medical costs with cigarette taxes, etc.
If they file income taxes, they can take payments made as a credit if they owe more taxes through higher income.