You have it right. There is always a negotiation to get a law through Congress. I would also suggest that simply not breaking laws is not enough I would add that they have to be welfare free for several years (negotiable) and their kids have to be making normal progress in school (negotiation about what is normal progress) and no gang member support, and working at some job. (non-negotiable). Finally, normal progress towards learning English. If they have been here long enough, an English exam might be preferable.
KC:
Thanks for the comments.