Eugene Volokh wrote a very convincing post discussing the question of whether airport searches violate the Fourth Amendment or not. Eugene (not surprisingly for a security-conscious blogger) came down pretty squarely on the side of the searches, but had a good reason: the Amendment does not protect against searches without probable cause, but merely if they are "unreasonable"... a much weaker criterion.

What interested me were a few comments he made in support of this conclusion:

"reasonable[ness]" is the test that the Framers gave us -- and even though it has been in some situations instantiated through a set of brighter-line rules, I don't think that the vagueness and potential breadth of allowed searches can practically be avoided, precisely because some searches are indeed necessary to save people's lives.

Ok, so this sets Volokh down as a pretty strict constructionist... the important point is that it is "the test that the Framers gave us", and while open to the "it isn't the 18th century any more" critique, it's certainly a valid perspective, especially considering the extraordinary reverence that Americans have in the founding fathers and the belief that they wrote a document that is as relevant today as it was then.

However, this...

The Constitution is not just a charter for preserving our liberties against oppressive government, though it does try to do that. It is also a device for creating a government that can preserve our lives, liberties, and property against foreign and domestic enemies who would take them away. For the government to be able to do this, it must have various powers, including in many instances the power to search and seize us. We may want to see that power limited in various ways -- but the power to stop and screen passengers strikes me as eminently reasonable and necessary.

...confused me greatly. I think one thing that pretty much everybody agrees on about the founders is that they simply didn't trust government as far as they could throw it, and wrote a constitution that was painfully and obviously explicit about that very point. Volokh, however, has taken a rather different perspective- that the government can be permitted to act in order to defend us against "foreign and domestic enemies". This line of argument, to be blunt, defends monstrosities. It was the first argument that was used by the Soviets (with some justification- the United States really was trying to destroy them, although the Soviets did a pretty damned good job themselves) and by pretty much every tinpot dictator worldwide whenever he removes civil rights. Indeed, anybody familiar with the Lockean set of arguments would say that any act against even petty criminals is one against "domestic enemies". The precise reason why the Constitution is important is because it sets the ground rules by which the government can go after these "enemies, domestic and foreign", and so that the government can use strategies that keep this in mind- or amend the Constitution, with all the bad press and unrest that such a thing would no doubt entail. You can't arbitrarily throw away Constitutional rights because the threat greater than some petty thug, or else you've just justified even the most murderous third-world dictator and his "I was just defending the people against domestic enemies" line of bull. More than that, you open the door wide for such things in the United States, and I know for certain that the Framers wouldn't have wanted anything like that.

Then again, I always come back to the same point whenever I hear this sort of argument... It's not the Constitution of the Framers, but of the people of the United States. Although it was written by, yes, learned men in the past, it doesn't belong to them- it belongs to the current and future citizenry. If it fails to serve their needs, their interests, and to protect their rights, then it doesn't matter whether it's absolutely accurate to the Framer's intent... it has failed, and should be amended or (if such a thing can be ethically done in the case of Amendments with fairly wide interpretations, such as the Ninth) reinterpreted. Should this be done lightly? No, of course not, the United States is built on the concept of constitutional supremacy. Still, the option does exist.
(I'm aware this is somewhat contradictory, but I'm mostly exploring ideas here, rather than arguing a position.)

One thing to remember? This isn't a binary situation. There is some latitude between "let the terrorists win" and "give the government the right to do anything it pleases", and the key goal is to figure out where to draw that line, not necessarily which side of it you need to be on.

Edit: fixed up a few spelling mistakes.