EUGENE VOLOKH RESPONDS to the National Association of Hispanic Journalists on appropriate nomenclature:

As between “illegal alien” and “undocumented immigrant,” it strikes me that the former is more reflective of what is actually going on, for better or worse, and the latter is an attempt to hide what is actually going on. If one is writing political advocacy, one may deliberately choose the latter term (though even then one risks losing credibility). But if one is trying to be an objective journalist, I think “illegal alien” or “illegal immigrant” is the more objective and more candid way of putting things.

But they’re not trying to be objective journalists. They’re trying to be Hispanic journalists, which they clearly see as something different.