Giving full benefit of the doubt: the White House can't be used to leverage relatively small armament to control of a missile that can take down a skyscraper.

Now, I'm pretty sure that with reinforced cockpit doors, passenger awareness that a hijacking isn't likely to lead merely to a few days on the tarmac in a third-world country, and an air force much more likely to react precipitously to a passenger jet deviating towards a major downtown, that's become very unlikely with aircraft. But while they also mean to protect the planes themselves from shoe-bombers, I'd say that's the last war the TSA is committed to fighting.