After Ground Zero occurred, everyone stood together as one nation against a threat from outside.
The biggest difference was in leadership. The Mayor of New York called for cooperation and calm. He actively coordinated the emergency response.
There is also the difference in scale -
The attack of 11 September destroyed a few square blocks, not an entire city. The total affected areas were a small area in New York City, Washington and a field in Pennsylvania, not 90,000 square miles. New York still had functioning power, communications and a viable police force.
Still, even with the difference in scale I have no doubt that the situation in New Orleans would have been far better if Mayor Ray Nagin had exerted leadership instead of political posturing, assigning blame to everyone but himself, his city council, the State of Louisiana and his political party. He has played to his constituency and not to the emergency.
The total affected areas were a small area in New York City, Washington and a field in Pennsylvania, not 90,000 square miles. New York still had functioning power, communications and a viable police force. Exactly.
To compare this to the 9/11 attacks is ludicrous.
However, if Giuliani had been in charge of New Orleans, he'd have carried everyone out on his back if need be before the hurricane hit. Or at least thrown a bucket on the school buses and said "Hit the road!"
And he probably wouldn't have had so many welfare dependents and criminals in any city he ran.