The "right to travel" is not just a pleasant notion; it's a constitutional guarantee. Although it's not mentioned in the text, the Supreme Court has long treated it as thunderously obvious. In 1900, it said that "the right to remove from one place to another according to inclination is an attribute of personal liberty" firmly "secured by the Fourteenth Amendment and by other provisions of the Constitution."
The document also guarantees the right of due process, which those on the no-fly list can only dream about. The decision is made in secret by unseen officials who provide no reasons, entertain no disputes and allow no independent review. You could get a fairer hearing from a crowd toting tar and feathers.
This is only one of the defects in the system. A bigger one is why the list is needed at all. Since the 9/11 hijackings, various steps have been taken to prevent a repetition -- reinforcing cockpit doors, putting thousands of armed marshals on flights, screening liquids and patting down travelers. Passengers, meanwhile, will no longer sit quietly if someone becomes a problem.
The Transportation Security Administration feels so confident about its ability to defuse genuine risks that it's decided to allow small knives on board aircraft. But if the government can keep troublemakers from employing the weapons they need, the troublemakers will have only pitifully ineffectual options -- which means they aren't likely to fly in the first place.
The nice thing about these other security measures is that they work not only against anyone who is deemed dangerous but also anyone who is not. And they impede the guilty without inflicting serious harm on the innocent.
Maybe the people who compile the no-fly list can say the same thing. But I don't really want to take their word for it. If Ted Kennedy were around, he wouldn't either.