This really does not make sense : why don't these people help these people prepare to move out of the USA?
In some EU countries, France actually, one association has managed to convince 3,000 people ( mostly Afghans) to go home as they receive business training with very experienced entrepreneurs, a grant, and a follow up back home. It is not compulsory, but they have to stay home for at least 5 years ( need to check this , as it could be longer). But to come to that, some people had to take on themselves to understand the illegal immigrants points of view, and to put attractive offer for these immigrants to prefer striking it rich home, rather than wasting their time in awful jobs. Obviously these type of things are only effective, if the foreign policy follows ( no support for overseas dictators, multinational overseas have to pay for their own security and not use the state coffers for it, etc.).