Drinking age laws are so discriminatory! And, what's worse, they harass people who are of legal drinking age! People of legal drinking age, who look like they could be too young to drink, are often forced to prove that they are of legal drinking age. Yet older people rarely have to show any form of identification! Thus legal drinking age laws discriminate against young looking people, and harass people who are of a legal drinking age.
Sound familiar? This is the argument being leveled against the Arizona illegal immigration law. When I make the exact same argument about legal drinking age laws the ridiculous nature of the argument is revealed. Yet many people continue to make the argument with a straight face.
Young looking people are statistically much more likely to be under the legal drinking age than are older looking people. Thus young looking people get carded more often. Mexican and latino looking people in the state of Arizona are statistically much more likely to be an illegal immigrant than white, black or Asians in that same state. Thus they will be more highly scrutinized in that regard. There's nothing unfair or unjust about recognizing and isolating different behaviors among different groups. Different groups in different areas behave differently and have different characteristics. To ignore this, or to call for law enforcement to ignore this, is the equivalent of asking police to shut off a functioning, logical, helpful part of their brain, that they should be using to their job more efficiently.
It's not something that they will trumpet, but intelligent detective and police work is absolutely dependent on all types of profiling, including racial. "The suspect is a 6'1" white male in blue jeans" - when this is the description of a suspect of a crime, should police highly scrutinize a 5'4" black woman in a skirt as the likely culprit? I should hope not.