SOME MORE THOUGHTS

The 14th Amendment:
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

EQUAL PROTECTION OF ALL CITIZENS (I'm not arguing about foreign nationals).
Explain how choosing people out of a line because of the color of their skin is equal treatment.

I understand how you can say "oh, just one little extra search for brown people at the airport" but this discussion really isn't about one small example, at least not for me. I certainly do understand your point, Israel has a policy of thoroughly checking all young brown men at airports and they haven't had a terrorist incident on a plane in 30 years. But, i absolutely give you the "slippery slope" argument. There must be a thorough and fair way to check all passengers boarding planes.

"I am more willing to entertain restrictions that affect all of us like identity cards and more intrusive X-ray procedures at airports - and am somewhat more skeptical of restrictions that affect only some of us, like those that focus on immigrants or single out people by nationality."
-Walter Dellinger, former Acting Solicitor General during the Clinton Administration