You are playing the "All or Nothing" game.
Slick, but no cigar.
It's not "12 million tomorrow, or NONE, EVER".
Can't deport all 12 million at once? Then do it the same way they CAME here -- a few thousand at a time.
Even if the cops only nab ONE OUT OF TEN, instead of giving them ALL a pass, as is done now, the OTHER NINE will be crapping their pantaloons worrying about when THEY get the brass ring in the nose.
Then, you ENFORCE the law against employers hiring them.
Finally, you offer a $1,000 reward, cash money, tax-free, to any CITIZEN who turns in an employer who hires them. Add an extra $100 to the reward for each one he's nabbed with.
I guaran-f'n-tee you the "problem" will solve ITSELF, faster than you can say "where'd they go?"
It's not a question of "how" -- the problem is NOT difficult to solve.
It is a question of WILL -- and, of AGENDA.
Our Glorious Leaders do NOT want to lose the New Plantation Workers.
once the media starts airing reports of women and children being herded from courtrooms onto buses, headed for the border (and what makes you think mexico will take them back?) - public opinion will flip on this in 24 hours, and you'll have americans supporting amnesty.
the employer stuff you mention - no one will worry about that. no one will blink at enforcement of zoning laws, where these people live 40 to a house or 20 to an apartment. fine the landlords, arrest them. we can incentivize the status quo to get many illegals to deport themselves, without a roundup, and millions of trials, appeals, etc.