The former illegals would have first dibs on the available jobs. It would be a two trench system. In reality, it would not make much difference, because the employers would hire first their former employees voluntarily, to the extent they can. But if it turns Bush on ... ?
Guest workers, green cards, and no rewards for illegals would sell to just about everyone but Bush. I think even Tancredo might play along, but maybe that's my optimism.
Rewarding illegals is the whole ballgame for those who oppose the Bush plan, and for them the status quo is preferable to giving an inch on that. Bush can have just about everything else he wants for a historic immigration reform, but he will overreach and insist on legalizing illegal aliens, provoking a whole lot of ill will in the GOP that will not be beneficial to the rest of his agenda. He seems to have gotten it into his head that he has a mandate on something he soft-pedalled during the campaign.