The one question that nobody seems to be able to adequately answer in regard to a guest worker program is this: Who or what is going to make the guest workers leave the United States and return to their home countries after their allotted time in the guest worker program has expired?
As I understand it, the workers will turn themselves in after their allotted time and return home for a period and then return here again. At least that is one of the three programs I am aware of. It may not be the president's.
The carrot for cooperation is to be able to become a citizen after five years with good behavior. The stick is for them to be returned and not allowed to return if they don't cooperate. The problem is finding them and catching them. That is why controlling the border is still necessary.
Once such a program is installed it will be back to where it was before the massive influx, some cooperating with the system to become citizens and some being outlaws. The idea is to provide a conduit between willing workers and sponsoring employers.