The debate between left and right over whether “profiling” is an appropriate tool, is one of several aspects of the “War on Terror” where people talking about something that is essentially a non-issue. The debate is welcomed by al Qaeda and other Islamic terrorist groups, since it diverts attention from more serious discussion of tactics and strategy.
Information from various intelligence agencies suggests that even before September 11, 2001, al Qaeda began actively recruiting “Western” looking people, men and women, for the purpose of circumventing any resort to profiling. They have apparently been having some success.
I suppose these efforts raise their costs of operation somewhat, but probably not enough to make profiling especially helpful.