Some ideas are so simple. If some Muslims want to blow up airplanes, put them in a separate screening line and subject them to greater scrutiny. "Profiling in pursuit of freedom is no vice. We must keep this country safe from its enemies." Or something like that.
Forget about the fact that you can't spot Muslims on sight. I've known Christian Palestinians and Syrians. Many Arabs have other faiths or are not religious in any way. Do they join the "Muslim line"? Do we consider Nigerians and other Africans Muslims because they're from Africa where there are lots of Muslims? And what about Muslims who aren't of Arabic or African descent? Do we make people put their religions on their passports? Or maybe we just stamp a big "M" on the passports of Muslims.
But let's say someone figures out how to herd all the Muslims into one security line and subject them to more intense screening. And let's also say that will stop the 1-in-100,000 (1-in-a-million?) passenger who might otherwise wear explosives in his shoe or his underwear.
Will we be safer?
Weigh that possible thwarting of an attack against the terrorist recruiting value of the Muslims-only line. "So," those bent on bringing terror to the U.S. will say, "you continue to tell us Muslims are treated well in the U.S.? You're not discriminated against? You have all those supposed rights and freedoms.just like everyone else? Yet they herd you into a separate line and poke and prod you like cattle, like criminals, like slaves, simply because of your faith. Their actions prove they hate you, both in the U.S. and in the rest of the world where they kill Muslims indiscriminately. They must be shown that they cannot get away with this. They may be able to keep explosives off of planes, but there are many other soft targets in the country . . ." And so on.
I feel safer already.