The issue of immigration is so complicated that I haven't yet spent the time to fully digest all of it. Perhaps the new immigration bill is good, maybe it's bad. But, I don't think that American immigration policy should give a rat's a** whether Mexicans are "wary of" it.
I welcome anyone who comes here peacefully and is willing to pay for their own existence. For a free society, infusions of productive, law-abiding people can't be a bad thing.
But, the idea that Mexicans (or anyone else) are somehow entitled to come here and work is erroneous and offensive. The fact that they can make more here than in Mexico doesn't create on their part a claim on America. Ultimately, they should be happy with whatever they get.