Most immigrants who can come do so at the luxury of those that can't come. When they arrive, many have resources available to them in terms of family and community.
And when they go into the businesses they go to, they don't go into them with shame. Many immigrant businesses are cash business - more lucrative versions of what they had back home.
You have all these ignorant people arguing over they should get better jobs and how they're so poor and yada yada yada when much of the wealth of foreigners is simply economically immeasurable.
http://www.cato.org/special/friedman/desoto/bio.html
-Rudey