Goebbels once said that there is no lie so stupid that after constant repetition it won't be believed. All the Left needs to do is to let their anchor / reporter buddies keep repeating the lie that it was a detailed warning and sooner or later, it would become part of conventional wisdom that Bush knew precisely everything that would happen on September 11th.
That's why I'm urging everyone to keep an eye on the news media and be prepared to raise hell (phone calls, letters to the editor, faxes, etc.) at any form of distortion, no matter how innocuous it may seem. Deny them the pleasure of inflicting a death by a thousand cuts.
Look at Rather and the Rats in 1992 when the mantra was "worst economy in 50 years", "Bush cooked the books", "Yatta!".
Before the end of the year (but after the November election), Dems were saying that things weren't as bad as they seemed. The numbers weren't "cooked" to appear to be better.
"It's the economy, stupid!" - Bill Clinton campaign slogan
"Have you ever had the feeling that you're being cheated?" - Johnny "Rotten" Lydon at his 'final' Sex Pistols concert