partially responsible for the 911 attack because he didn't do enough to prevent it. That kind of large-scale attack is difficult to pull off, and could have easily been prevented if he had maintained the same level of vigilance as the Bill Clinton administration. But that's the nature of W, he is a slacker.
If you read that memo, it did contain some specifics like hijacking airlines.
http://www.cnn.com/2004/ALLPOLITICS/04/10/august6.memo/