I'm really sick of reading fairytale stuff like this. The most he could've done is notify the airlines to report any strange behavior as soon as possible. That would still be under the discretion of the profit-hungry, corner-cutting airlines. I'm not saying Bush handled things perfectly... but things aren't always as simple as "well he should've just notified thousands of people, caused chaos in airports, and not let the public know" (if they knew, it would've caused huge problems for something that may not even happen.. keep in mind, threats come in constantly).
Increased air traffic security:
A) Infringes on the convenience and usability of airports.

Costs tons of money and man-power.
C) Worries the public
All based on threats that roll into the white house like overpriced champagne?
So if you were president, upon every threat, you'd call each of the airports in the US and tell them to "increase security"? How? What would you expect them to do? You can't tell them "stop everyone who looks like a terrorist". "We might be attacked... make sure it doesn't happen.". Right.