The million-dollar question is this: what, exactly, constitutes reasonable suspicion of illegal residency? In effect: what does a suspected illegal alien look like?

You can say "Okay guyz, no racial profiling," all you want, but until you can find a workable definition of "reasonable suspicion" for illegality that does not operate based on an individual's appearance and/or cultural norms that apply to many Hispanics, including those who are in the country legally, racial profiling is exactly what is going to happen.