People have believed what appeals to them for thousands of years. It does not mean its truthful. What do intelligent people logically deduce?
The levee failure is true. Why did the levee fail when stressed with high water and wind? Here are some possibilities:
1. It could have been sabotaged by Bush, foreigh terrorists, republicans, or democrats...
2. It could have failed because it was poorly built or that there was fraud in the conctruction.
3. It could have failed because it was never designed to handle this load.
4. It could have failed because in addition to not being designed strongly enough, it suffered from a period of negletct. Have I covered enough?
Now, I have heard that the technical community will look into these matters. But a conspiracy advocate will not trust the results of an "expert" study. I have heard that the levee broke in an area that was recently "upgraded". This means that long neglect was likely not the cause.
Now terrorists only wish they had thought of this, a disaster on the scale that Al Queda likes but so easy to cause that it could happen by itself. (Only it took a hurricane), the terrorists would have done it at Mardi Gras. So lets drop the idea of terrorism.
But this logic also means that Bush and republicans probably did not do it too. Because the hurricane is unpredictable and if they wanted to do in the black people, they would not have had the patience to wait for just the right hurricane. It becomes more and more reasonable to look at the hurricane for the solution.
If the hurricane had something to do with the problem, it probably had a lot to do with the problem. It also trashed I 10 and the causeway across the Lake. Wow, it must have been a powerful storm to do all that damage in Mississippi. Maybe the storm did it?
Note that we still have the recent upgrade and the possibility of contractor or worker fraud to look at. I don't put Bush in much harm for this. If fraud and corruption helpped the levee to fail, I would look to the democratic machine and the local "fat cats" to blame. Is this logical or what?
Just as long as you take care to remember; "In the land of the blind, the one eyed man will probably be executed."
You forgot to mention that earthen levees take time after being "upgraded" to re-compact and reach their full strength.
I would point out one additional factor. For a period of time after rebuilding/repair, the soil has not settled and is more prone to erosion. If the flood wall was overtopped and water undermined the newly compacted soil, that could have caused subsidence and collapse.
Also, there are persistent stories that a drifting barge or boat struck the flood wall and breached it. Certainly there was lots of stuff floating around -- photos of the 17th St. Canal showed a backup of floating debris at every bridge.