If only Bush had received a warning prior to 9/11 that Bin Laden was determined to attack the US. Like in a memo or something.
Look, I'm not blaming Bush for 9/11. The fault for that lies squarely on the terrorist jackasses who did it. I don't even think Bush could have done much to stop the attacks. That said, I think it's clear the Bush administration considered Bin Laden a non-threat and instead was focused on finding a reason to attack Iraq. And the idea that 9/11 can be blamed on Clinton is silly. Even if Clinton had a chance to kill Bin Laden and didn't not, which is debatable, it's still not his fault that Bin Laden did something months after Clinton left office.
My take on it is quite simply whether it was intelligence approaching President Clinton or President Bush or President <fill in the blank> with the proposal that an attack might be imminent no one could have predicted what would really happen.
And that attack by the enemy would be "a batch of guys getting on planes with box cutters, hijacking the planes and flying them into the WTC and the Pentagon" I know any rational human being, including a President is thinking "I want what they're smoking/drinking" OR
thinking "note to self: restrict all access to Art Bell and Coast to Coast to all CIA".
Before 9/11 happened no one ever could have dreamed up this case scenario.
So although both Presidents missed the boat on this, I'm sorry. I'm forgiving because it was the most unlikely scenario on the planet.