Brought in legally under temporary work-visa programs. This is another problem Trump has addressed by adovating welfare to work programs if he's president. For these types of jobs, our wonderful government has created the situation where many US citizens are better off on means tested poverty programs than working in lower paying jobs.
This needs to be addressed and Trump is the only one I've mention it recently, maybe since Newt Gingrich pushed welfare reform in the '90s.
Two of his companies, Trump Model Management and Trump Management Group LLC, have sought visas for nearly 250 foreign fashion models, the records show.
http://www.newsweek.com/trump-companies-seek-visas-foreign-workers-359043