Police officers are already heavy handed assholes. I doubt this law will actually result in a net increase in people being treated like children by law enforcement agents.
And I seriously doubt that you're going to be shipped off to Mexico for looking Hispanic. Yeah, you might catch some shit from a cop (keyword: might) but I don't think you really have reason to complain about this one law whose enforcement will probably not result in the kinds of blatant discrimination you're talking about -- at least not in levels greater than those that already occur in the southern and southwestern United States.
My best economics teacher so far has been an Iranian immigrant with hilariously broken English. He arrived dirt poor, thirty years old, not knowing a single word of English besides hotdog. He learned English, went to school, married an attractive white woman (only including that for lulz) and got a doctorate in International Trade & Finance.
He doesn't whine or complain about discrimination, which he probably does experience, but rather is grateful for being in a country where he is actually allowed to go to school and earn a PhD and not have to wait in line for his family's weekly chicken or worry about the secret police knocking on his door in the middle of the night (which does happen there). He brought his aunt here and she broke down in tears after taking one step inside a generic grocery store.
I think people who come here from nanny states feel like they're not being properly babied and coddled, whereas people who come here from police states are wowed and amazed and grateful to Allah for all the freedom and prosperity at their fingertips.