The whole only-people-with-reason-to-fear argument, to put it mildly, has not been a historical friend of liberty. Nor is it usually accurate. If you are a legal resident immigrant from Mexico, you have plenty of “reason to complain” about this law, because now it’s more likely that you are going to be pulled over by an Arizona cop.
I don’t actually take the “only-people-with-reason-to-fear” position: I recognize all government power can be, and typically is, abused. But in principle the Arizona law tries to balance two competing interests — trying to reduce an illegal population that is mostly Hispanic while protecting the rights of Hispanic legal residents and citizens, who are also large in number. Whether it works out that way in practice, we’ll soon see. But in the context of federal non-enforcement of the border and immigration-related problems affecting Arizonans of all races and ethnicities, it simply makes no sense to not use routine police contacts with illegal immigrants to determine their legal status.
As Welch himself observes, the problems associated with illegal immigration are real and they are faced by decent, law-abiding people in Arizona every day. That is why this law was enacted with 70 percent popular approval. There is no truly surgical or cost-free way to deal with those problems. And with all due respect to my libertarian friends, that includes legalization: even fixing the immigration black market won’t prove cost-free.