In general, I see the Arizona law as a reaction to the national government's refusal to enforce "the people's" duly enacted laws on illegal immigration. Arizona's act is the appropriate response given by our federal system in which the states act as a check against the national government's abuse or inaction and the national government checks abuses by the states. Recourse to using the legitimate legislative authority of the state to counter and protest misdeeds of the national executive branch is one of the few actions "the people" can have against an unresponsive national government under our federal system of republican self-governance short of revolution. Changing Congress is the solution in the long term but denying states the ability to serve as an effective counter to the national government's abuse or inaction does not assist the cause of republican self-government. As we discussed before, this same mechanism worked in reverse during the 50's and 60's when some states refused to enforce civil rights laws.
I also take exception to the constant reference in the federal government's lawsuit referring to immigration laws as "federal" laws and using this as the reason states cannot act to enforce them. While these laws were passed by Congress -- all laws, whether state or federal, are "the people's" laws and all legislative authority rests with the people in a republican system of self-government. These are "our" laws that the national government is refusing to enforce not "their" laws. The laws belong to the people not to "the government" national or state. The federal (national) government does not "own" these laws, the executive branch exists to see that our laws (the people's laws) are faithfully executed. The executive branch cannot arbitrarily pick and choose which laws will be enforced and which will not. When it does this, as it has on the issue of illegal immigration, it is essentially vetoing the people's duly enacted laws and is in effect denying us our constitutional right to a "republican" form of government assured us in the Constitution.
I also have read, but have not confirmed myself, that the federal Judge in this case accepted a brief from the government of Mexico. If that is indeed true, it raises serious questions of allowing foreign influence in our constitutional system of self-government (this also could be interpreted as a violation of the Constitution's guarantee of a "republican" form of government). Like almost all issues these days, this case is essentially about who governs -- the sovereign people or some other elite group whether it be judges, the executive branch, the nation of Mexico or some other unelected and unaccountable groups.
New Revolution Now Contributor