If Rita would have gone over Galveston and Houston as a CAT 4 or 5 you would now be seeing the failures of the evacuation as you did in New Orleans That's conjecture isn't it? Since it didn't happen. A successful evacuation takes place before a hurricane hits, not after.
Nagin let school busses sit idly by while demanding Grayhound busses from the feds. That's a complete failure of leadership.
Somewhere between 80 and 90% of New Orleans evacuated before Katrina hit.
I call that a successful evacuation.