If those taxes add to the SS "surplus," the net result is an increase in the national debt. Any "surplus" is put into the General fund to be spent elsewhere and the amount of the "surplus" is converted into non-market T-bills [read IOUs] and placed into the SSTF, which represents a liability and is held as part of the National Debt as "Intragovernmental holdings." So the net effect of legalizing the status of the illegals is to add to our national debt.
It is also worth remembering that once the status of the illegals is made legal, they can bring in aged parents, spouses, and children who can draw on the various entitlement and social systems. There are anywhere from 13 to 20 million illegals, so they will be able to bring in almost immediately tens of millions more under chain migration and family reunification laws. If that happens, the US is finished as we know it.
The real sleeping giant of this whole fiasco is the amount of children being born here. If we don’t address that we are just as screwed. Even IF we start deporting and they take their children with them, ALL can return at 18.