An uneducated illiterate workforce is somewhat useless related to what is needed. Massive sums of money are in play to push a One World Social Justice Economic model. Absorbing the cost of other countries liabilities is part of that game. Those liabilities are not just monetary, but they are also human.
For example, here in Southern California, "Spanification" of a workforce (Meaning Spanish as the common language in the workforce) is a real and economically damaging result of the governments refusal to enforce immigration laws already on the books. Of course, then there is the harm that has been done to public education, etc.
The suggestion that illegal aliens made legal will help secure Social Security and other entitlement programs is laughable at best. In my experience, most illegal aliens use stolen or fraudulent ID's, and have SS and other taxes withheld, which they will never collect.