Do you really think the police can't make up a plausible reason for stopping someone if they want to?
Why do you think Obama’s DOJ doesn’t want to improve the situation for this friend of yours?
For the same reason you started beating your husband - in other words, the question is a logical fallacy.
The Arizona law would make more stringent requirements for what officers can check, specifically to protect against racially-based queries. The rationale for the DOJ’s resistance to that law makes no sense with what the law actually does.
The people who come here illegally are spoiling things for those who keep the laws, because everybody is suspect. If there were one or two illegals in a town people wouldn’t worry about it. If the place is overrun with them a person can’t help but wonder about everybody they see.
The fact of the matter is that as long as the border is unprotected so that Arizona is overrun with illegals, the people are going to be suspicious of everybody who looks Mexican that they don’t already know is legal. That’s just a fact of life. If Obama wanted to solve that situation he would protect the border - which he won’t do. Why is that?