20-20 hindsight is always perfect in telling us what we should have known after the fact. And some folks what that to be the ‘true foresight’ and can’t accept the reality that it isn’t.
But they did know an attack was imminent! They were sitting on a request to increase covert operations against Al-qaeda since March! Shoddy immigration policies were in effect and are STILL in effect to this day, letting random Islamic cretins from Saudi Arabia lie all over their applications and still get approved.
They knew it was coming and didn't take it seriously until after it happened. That's just a fact. You can blame Clinton for creating a great big fog in our intelligence agencies; you can blame the Dems for making it harder for Bush to get his people in; but you can't claim that Bush had terrorism as his top priority, even after repeated warnings of something in the works.