You left out the most significant group: Illegals who entered unlawfully.
Basically, under 245(i), any border-jumper with a family member who's a legal resident of the United States can qualify for this Amnesty if they come up with a grand.
That's less than coyotes charge.
I have to admit I'm pretty astonished at the organized 'lessons' of how to qualify available on the Google search.... Looks like some are making alot of money on these scams.