A better source for this claim might have been the August 6th, 2001 memo that the president et al saw titled 'Bin Laden determined to attack within US' that described 'preparations for hijacking' [passenger planes]. Its all in black and white.. :read:
Couple that with the disregarded Richard Clarke anti-Al Qaeda suggestions (which Rice denied existed on 3/22/04, saying no Al Qaeda initiatives had been handed over to the new administration) and the president's 'Saddam, Iraq. Find the connection' statement in the days following 9/11, and it begins to paint a pretty clear picture as to the (at best) negligence beforehand and the ideology-driven policy afterwards.