None of them are "hard cases" at all.
I think the concern is the one best expressed by this lady on TV yesterday who claims she's a Bishop of some kind: "Our ministers, preachers and rabbis in our churches and synagogues tell us they have members who fear being detained".
SYNAGOGUES? People in synagogues ~ valid members ~ fear being detained because they presumably don't carry IDs of any kind?
There's a lot of phoney baloney going around regarding this law ~ that it targets Jews is a part of that.
If Mexican Jews belong to synagogues in Arizona, then what about those Jews who were being burned at the stake in Mexico in the 1840s? I thought all but a handful of Mexican Jews abandoned that country over that issue, and those who remain live mostly in Juarez (and presumably own helicopters for quick exits if necessary).
All of which takes us to the point of "what people fear", and I hope they "fear a lot of stuff" and return to their country and help it join civilization again.
None of this addresses what I said. Either Arizona will never dare to push the law past the symbolic point, or else they will invite intolerable outcry and/or being overruled in Federal court.