Larry --
There is enough blame to spread around if you look hard enough. But the hard fact remains that 9/11 happened on Bush's watch, and the PDBs, I'm given to understand, are not idle e-mails but contain some of the most important information a President has to deal with each day. There were any number of warnings, and even if you can't bring yourself to accept Richard Clarke's rendition of things, it's hard to overlook such vacuous comments as Rice's, "No one ever dreamed someone would use an airplane ..."
Am I trying lay 9/11 entirely on Bush's shoulders? No. But I don't think you can give him a pass, either.