this is probably one of the more touchy subject in the past few years regarding the government's handling of illegal immigration in the country. There is a big population of illegal immigrants come from illegal college students staying after graduation in hopes of getting a job sponsor or just simply staying in the country.
http://latimesblogs.latimes.com/lanow/2010/11/dream-act-should-illegal-immigrant-college-students-have-path-to-citizenship.html