I think the people in New Orleans might just be stupid enough to do it. They do live in a city that is below sea level... and has been wiped off the earth more than once by a natural disaster.
Pretty dumb if you ask me.
I fully agree with you that Brad Pitt would make a terrible mayor, probably worse than our present mayor, Hizzoner C. Ray Nagin, but not for the reason that you give.
First, we do have a lot of intellectually challenged voters (I'm not one of the because I'm too young to vote) in New Orleans and they all tend to vote for their own self interest. But, are we that different than most people who choose their leaders around the USA. Just look at the U.S. Congress as an example of the voters' intelligence.
Second, We live in New Orleans because we love our city, even though most of us live below sea level. If everyone moved away from their home because they feared a natural disaster 300 million people all would be living in eastern Montana, North or South Dakota, and perhaps central Canada. I don't see a lot of people moving from California in fear of wildfires or earthquakes, or people moving from Tornado Alley or Atlantic Coast of the U.S. because they have tornados or Atlantic hurricanes there.
That being said, Brad Pitt, if he ran, would not be elected for following reasons:
1.) He is an outsider and doesn't know who are the "real" players in New Orleans politics. Those power brokers probably wouldn't take him seriously.
2.) He is an actor. Would he be willing to give up his acting career to become the major of a struggling southern city with all it problems? I don't think so.
3.) He's the wrong color. Like it or not, New Orleans is a racially divided city. We have a deep race problem here that effects the city at all levels. My city is 56% African-American. He would have a hard time defeating a strong African American opponent. There are several powerful African American politicians already set to run for mayor. I am not saying it can't be done. But it would be an upset if he were to beat a popular African American opponent.
Anyway those are my reasons why Brad Pitt would do better staying an actor and continuing his support of rebuilding the parts of this city that were the heaviest hit by Hurricane Katrina.