20 million? no, nowhere near that number have US citizen children and their own homes. those are the only two segments I would put on the path to legal status - as part of a deal that offered border security and employer sanctions. none of this "you've been here for 5 years, show us your pay stubs, and you're in" nonsense.
the folks you want to flow back - are single males who come here only to work and send money back, who engage in crimes, who live 30-40 men to a 4 room house. those are the ones we want to dis-incentivize to remain.
I don't believe there's a snowball's chance in hadies of that distiction being made. I appreciate your clarification though.