What does this have to do with the Arizona law?
The Arizona law targets those who police suspect are not from the United States. Even with strict immigration controls, these drug cartels would exist because of high demand for drugs from the United States.
Hoping that random checks on citizens will reduce the number of Mexican drug operatives in the US is a pipe dream.
Closing the border, getting more national guard resources to the border or reducing the ridiculous demand for drugs from the United States is the answer to fight these powerful drug cartels, not randomly asking people for their papers.