Never mind there will likely be corruption and will have several "holes" for immigrants to pass through. After all, we always need a bogey man of some sort to point the finger at.
Also never mind that we never addressed why we need undocumented labor in the first place. The cost of food will go up likely. At some point the federal govt will have to subsidize food in order to make it affordable for middle and lower class citizens (for political reasons of course, you have to at least look like you're helping).