Why is racial profiling bad?

If you were robbed at gunpoint, and told the police that the man was 6'2", 250 pounds, and black, would it be reasonable for the police to stop all the black men in the area who were close to that description? Or would racial profiling be wrong? Should they also stop tall white and Hispanic men, so that they were not profiling? How about women? After all, we don't want to be sexual profiling.

Of course not. That would be ridiculous. So why is it wrong for a cop in Arizona to ask a Hispanic man driving a Ford Lobo (which is a truck sold in Mexico) who has already been stopped for a traffic violation for proof that he is here legally?

Deputy Bob Dalton and volunteer Heath Kowacz spotted a driver with a cracked windshield in a poor Phoenix neighborhood near a busy freeway. Dalton triggered the red and blue police lights and pulled over 28-year-old Alfredo Salas, who was born in Mexico but has lived in Phoenix with a resident alien card since 1993.
Dalton gave him a warning after Salas produced his license and registration and told him to get the windshield fixed.
Salas, a married father of two who installs granite, told The Associated Press that he was treated well but he wondered whether he was pulled over because his truck is a Ford Lobo.
"It's a Mexican truck so I don't know if they saw that and said, 'I wonder if he has papers or not,'" Salas said. "If that's the case, it kind of gets me upset."
The article says that 600 illegal aliens have been arrested during sweeps in Maricopa County, AZ since 2008. A drop in the bucket.

In the wake of the Federal court ruling that state and local authorities cannot enforce Federal immigration laws, I think that the states should refuse to enforce ALL Federal Laws: Immigration, Tax, Firearms, Drugs, and any other Federal Law that states currently enforce. States should no longer house Federal prisoners in State prisons. They have made their ruling, now let's see them enforce it.