1. Taxes and payroll deductions coming out of their pay may result in less money for the jobs they do now or less money than a job they can do off the books.
2. They all work now for people that are not going to add the overhead of legitimate operation. (If this weren't a problem, then why aren't they operating legitimately now?) If new guest workers become legitimate, they will lose the "illegal" jobs they have now. And make less money to send home.
3. Do you think that new guest workers will give an accurate address if they have a nefarious purpose for being here? Or for that matter, will they always have the same address they first give the government? Don't people come into this country now with Visas that expire and are nowhere to be found at their address on record?
This does very little for the illegals here, but it does enable MORE people to come here who aren't here now and I have no confidence we can find them once they come here if they do not want to be found. We can't even find them now. The ones that don't want to be found are the danger. So this is a security risk we shouldn't be taking. It allows potential terrorists to come here under the guise of legitimacy for three years, and then disappear once there is no answer at the 123 Elms street address we have on file.
What makes you say these people will return home after three years? Because the situation in Mexico has improved? LOL. They can stay here illegally, work a black labor market job, make more money.
It's not even the perks. The majority of illegal aliens have criminal backgrounds that will preclude them from participating in any immigration program.