There is a subtle truth here that it hard to explain to moderates. What would happen if we allowed ethnic profiling? Well, the truth is that any Muslim highjacking cells would put forward the least Arab-looking cell members to front the operation. Or they might even try to get their girlfriends to do it.
So pure ethnic profiling is not what is needed. Instead what is needed is subtle profiling based partly on ethnic appearance but mostly on dress, nature of luggage, demeanor, and behavior.
One additional thing. If we are really serious, any person who is who is suspected of being on a terrorist scouting mission will be carefully searched, seated between plainclothes air marshals, and THEN ALLOWED TO FLY. Serious security requires serious intelligence, and serious intelligence only comes from taking intelligent risks.
And guess why? It works! Simple commonsense.
The only people I know that are against it are radical socialists.