Originally Posted by Slims

....If a cop has a 'reasonable suspicion' a child is too young to be driving he can pull him over and ask for his drivers license.

Likewise if a police officer has a 'reasonable suspicion' that I am a burgler rather than the owner of a house he can legally check to find out.

How is this any different from any other crime?

If the cop has a reasonable suspicion you are committing a crime, he can typically check to find out yes/no.

Also, if Arizona has decided Illegal Immigration has become too great a problem, they should have the power (with the consent of it's citizens, which they have) to take measures to curb the issue.

It doesn't require 'racial' profiling to wonder if maybe a person who speaks no English, has a "Viva Mexico" bumper sticker and who does not possess a valid in-state ID card might not be a local.