Of course they waited, the US has never seen a storm like this in its entire history. What, they think this guy should have a crystal ball for a brain?
Last thing we need is FEMA agents forcing mandatory evacuations every time someone thinks a storm is going to hit. Only people that would like this are looters and Jack Booted thugs.
Be careful for what you ask for, some people are far too willing to supply it.
You know, I think you've hit on a big cause of this New Orleans fiasco: Governor Blanco and Mayor Nagin were TOO concerned about looking like jack-booted thugs by calling for a mandatory evacuation. They didn't want to look too heavy-handed in the eyes of those inner-city people who vote for them. In this specific case, with a Cat 5 hurricance heading straight for New Orleans, that was a big mistake because a mandatory evacuation was actually humane and necessary.