Jonah, most of your latest post is devoted to making points that I have already discussed — or, more frustratingly, points with which I agree, and with which I would have thought you would know that I agree, given all I have written over the years and in this very exchange about, for example, what is and isn’t profiling, why it can be justified in life-and-death situations (like terrorism and epidemics), the good work Heather Mac Donald has done in this area, and why mere disparate impact is not discrimination — see, e.g., the links I collected in my first post. Likewise, my first post emphasized that the Arizona statute now forbids the kind of profiling that we are discussing — the law didn’t at first — though I’m glad that you have reemphasized that point. (I can’t resist observing that your hypothetical border agent is unlikely to be scrutinizing the ethnic appearance of people “racing across the desert at night coming from Mexico.”)
So I think we are past the point of diminishing returns. I will just say again that it is poison to the American body politic and quite at odds with the principle of “E pluribus unum” for the government to stop people, or treat them differently after they have been stopped, because they share the ethnic appearance of other people who live in a country that sends us a lot of illegal immigrants, and that defending such discrimination makes it much harder to take conservatives seriously when we oppose politically correct discrimination. It is not true that I don’t think illegal immigration is a big problem, but I don’t think that the way to fight it is through institutionalized racial and ethnic discrimination — and apparently the elected representatives of the folks in Arizona have decided they agree with me, not you.