I'm not sure that the average traveler/voter can judge what is good security. What seems plain to me is that there is no totally safe place on this planet and that the better alternative to hoping that TSA has caught the bad guys, is to allow everyone the inalienable right to defend themselves. Could there be a downside to this? Yes, but at least they would be responsible for their own defense and would not have been disarmed by their own government.

So, in this brave new world, people that are afraid to use guns have lost the right to live because they didn't take up the responsibility to defend themselves?

Lifting the ban on guns/knives on an airplane is not going to make it safer to fly in a plane because "everyone will just pull out their guns and shoot the terrorist." What if the terrorist has a bomb strapped to him? What if he takes someone hostage? Just shoot through the hostage? What happens when a civilian decides they they are an expert marksman and tries to shoot the terrorist, but hits the hostage instead? Supposing that the terrorist was 'defeated' and everyone was safe, how would the legalities of that situation resolve? Is the person excused from killing an innocent because they were 'defending' their self?

With 9/11 in recent memory, it becomes clear that "don't let people defend themselves because someone might get hurt" is a weak argument at best.

Oh, and the scene in "Snakes on a Plane" where half the plane gets sucked out because of a few bullet holes is quite false.

The legalities work the same way they would on the ground.

If you want good security theater, just install some fancy looking machine that makes cool noises and every once in a while directs someone for a personal screening (regardless of whether they should be pulled out of line or not).

Also have a trained pro sitting on the sidelines pulling out people he finds suspect.

At a later point, maybe you can replace the fancy looking stuff with equipment that actually does something.