The bottomline is that Bush was talking about a program for workers here and also something to deal with future Mexican workers and I suppose else where that wanted to work.
For instance in the Debate "We need an earned-legalization program for people who have been here for a long time, stayed out of trouble, got a job, paid their taxes, and their kids are American. We got to start moving them toward full citizenship, out of the shadows."
That means to me that people who are here now. Versus a work program that gives temp work for a period of time that would be ongoing but would not have a citizenship path by itself. HE envisioned both