Pima County Sheriff Clarence Dupnik explains the problem with enforcing SB 1070 in today's Wall Street Journal:
The more fundamental problem with the law is its vague language. It requires law enforcement officials to demand papers from an individual when they have a "reasonable suspicion" that he is an illegal immigrant. The Preamble to the Declaration of Independence states that "all men are created equal" and that "they are endowed . . . with certain inalienable rights" including "Life, Liberty and the pursuit of Happiness." Those who look "suspiciously" like illegal immigrants will find their liberty in severe jeopardy and their pursuit of happiness disrupted—even if they are citizens or have lived, worked, paid taxes, and maybe even have served in our Armed Forces for decades.
When used in a law-enforcement context, "reasonable suspicion" is always understood to be subjective, but it must be capable of being articulated. In the case of identifying illegal immigrants, the ambiguity of what this "crime" looks like risks including an individual's appearance, which would seem to violate the Constitution's equal protection clause. Such ambiguity is especially dangerous when prescribed to an issue as fraught with emotion as that of illegal immigration.
I have an enormous amount of respect for the men and women of my department—the deputy sheriffs who respond to calls for assistance throughout Pima County every day of the week. I have no doubt that they make intelligent, compassionate and reasonable decisions countless times throughout their shifts. But no one can tell them what an illegal immigrant looks like and when it is ok to begin questioning a person along those lines. This law puts them in a no-win situation: They will be forced to offend and anger someone who is perhaps a citizen or here legally when they ask to see his papers—or be accused of nonfeasance because they do not.