E.g. Scalia's recent dissent on the Arizona case - http://www.supremeco...df/11-182b5e1.pdf
p.51
[...]
As is often the case, discussion of the dry legalities that are the proper object of our attention suppresses the very human realities that gave rise to the suit. Arizona bears the brunt of the countryÂs illegal immigration problem. Its citizens feel themselves under siege by large numbers of illegal immigrants who invade their property, strain their social services, and even place their lives in jeopardy. Federal officials have been unable to remedy the problem, and indeed have recently shown that they are unwilling to do so. Thousands of ArizonaÂs estimated 400,000 illegal immigrants  including not just children but men and women under 30  are now assured immunity from enforcement, and will be able to compete openly with Arizona citizens for employment.
Arizona has moved to protect its sovereignty  not in contradiction of federal law, but in complete compliance with it. The laws under challenge here do not extend or revise federal immigration restrictions, but merely enforce those restrictions more effectively. If securing its territory in this fashion is not within the power of Arizona, we should cease referring to it as a sovereign State. I dissent.
FWIW. My $0.02.
Cheers,
Scott.