Arizona and Immigration

I am a little baffled by this new Arizona state law that seems to just mean that Arizona state and local law enforcement will enforce a federal law. I thought that all law enforcement enforce all applicable laws.
Currently, federal law enforcement is stopping all traffic on roads close to the border, including I-10, and interviewing everyone. Presumably they are making decisions on a person's status at that time. Nobody seems to be complaining about this. Now the state wants to do the same thing. And there seems to be a problem.

While I am very disturbed by the idea of just targetting people of amerindian features I am also concerned about laws not being enforced. Law enforcement should be properly trained to look for the behavior and tendencies of illegal immigrants and question people based on that behavior. And not on any racial characteristics. Obviously, illegal immigrants come in all colors.

People are often accused of following idealogy and not science. Science can teach us the likely behaviors of people engaged in criminal activity and lead to more efficient targeting of suspects. And obviously not all odd behaviors mean criminal activities and the human judgement is required. And terminate any law enforcement officer who has a problem with this.

Effective law enforcement has always focused on behaviors. I have been stopped numerous times when I was doing something deemed odd. Like looking at my GPS while standing by a bridge. This seems more effective than stopping everyone on I-10.

UPDATE: 4/28/10 A Rasmussen poll suggests that Latinos in Arizona are in favor of the law. Also, consider the idea that Mexico is more dangerous than Iraq and the violence is spilling over into Arizona.