Its a start.
If they keep this up the illegals won't be able to find employment (eventually) and will leave on their own.
Next I can see Trickie Dickie Dirtbin in the well of the senate demanding unemployment compensation for illegals put out of a job.
Some might leave, but I believe a large majority will simple head underground to cash businesses, or become self-employed contractors, etc.
There are countless ways to make a living while steering clear of the IRS or immigration agents.
That is why Congress MUST boost penalties (or enforce) for simply BEING in the US illegally, so once an illegal is located, cops have the tools to incarcerate and deport. (Unfortunately, Frist and the GOP wussies lost their gonads recently).
The other business that will further grow is identity theft and ID forgery, UNLESS the Congress creates national fool-proof encrypted ID cards, which I wholeheartedly approve.
You say they will leave on their own if they lose their jobs.
I doubt it.Its better to be poor and jobless in America than Mexico.So I think they will just stay here and hustle up work somewhere else in the underground economy.