The NYT's David Brooks looks at the political repercussions of major disasters like Hurricane Katrina.

Some excerpts:

... In 1927, the great Mississippi flood rumbled down upon New Orleans. As (historian John) Barry writes in his account, "Rising Tide," the disaster ripped the veil off the genteel, feudal relations between whites and blacks, and revealed the festering iniquities. Blacks were rounded up into work camps and held by armed guards. They were prevented from leaving as the waters rose. A steamer, the Capitol, played "Bye Bye Blackbird" as it sailed away. The racist violence that followed the floods helped persuade many blacks to move north.

Civic leaders intentionally flooded poor and middle-class areas to ease the water's pressure on the city, and then reneged on promises to compensate those whose homes were destroyed. That helped fuel the populist anger that led to Huey Long's success. Across the country people demanded that the federal government get involved in disaster relief, helping to set the stage for the New Deal. The local civic elite turned insular and reactionary, and New Orleans never really recovered its preflood vibrancy.

We'd like to think that the stories of hurricanes and floods are always stories of people rallying together to give aid and comfort. And, indeed, each of America's great floods has prompted a popular response both generous and inspiring. But floods are also civic examinations. Amid all the stories that recur with every disaster - tales of sudden death and miraculous survival, the displacement and the disease - there is also the testing.

Civic arrangements work or they fail. Leaders are found worthy or wanting. What's happening in New Orleans and Mississippi today is a human tragedy. But take a close look at the people you see wandering, devastated, around New Orleans: they are predominantly black and poor. The political disturbances are still to come.