Sam Harris wrote "In Defense of Profiling" last week in which he makes the point that, in searching for people who are going to put bombs on planes, the TSA should focus on people who are likely to put bombs on planes. What it came out as was "start searching Muslims".
Profiling is usually just racism as far as most people are concerned. This is justified, because that's how it was used and defended for a long time. Pull over someone for driving while black. Actual profiling isn't like that. It's a long list of characteristics that help identify potential suspects. It's a forward defense, a way of seeking out potential offenders for deeper investigation. It's not going to tell you who's carrying a bomb or who robbed a bank, just what kind of person might have.
And it's a forward defense; it's not what you run when the enemies are at your gate, or might be. And that's because terrorists aren't stupid. When the guards start searching every unmarried, bearded Semite between fourteen and forty, the terrorists hand a rocket launcher to grandma Aisha, a bomb to pregnant Muslima, and a grenade to baby Ahmed.
Profiling specifically seeks out the usual suspects. Unfortunately, those guys aren't stupid, and they sure aren't going to come to you. Profiling deliberately does not seek out unusual suspects. It's not going to find the person who doesn't fit the profile, and that's who the usual suspect is going to recruit to actually carry the bomb onto the bus.
Finally, profiling based on race is pointlessly stupid. The vast majority of Muslims aren't terrorists. Frisking every last obvious Muslim isn't going to net any positive results; it'll waste a lot of time and money, and it will make a lot of people angry, and with good justification. I'm going to show you a picture of the typical American terrorist. Get ready, because it might set off a lot of alarm bells.
That's the sort of guy who's going to bomb a clinic or shoot a doctor. What, are you going to get the TSA to put checkpoints at the door of every church in Kansas and tell them to look for a clean-cut white guy whose severely plain shirt is tucked securely into his khaki pants? Because that's racial profiling.
Actual profiling would tell them to look for clean cut Christians who protest at clinics, who hand out leaflets advocating violence, who harass doctor's families and neighbors, who harass the women walking into clinics. That's how you catch an American terrorist. Profile the Christians. But if you want to prevent a terrorist from boarding a plane, profiling will only take you so far. You also need the exhaustive and annoying procedures that piss off everyone.