Leading article: A disaster that cut a presidency down to size

With his latest visit to New Orleans, George Bush must now hold the all-time record for the number of presidential trips to the Crescent City. The one occasion when he should have been there, however, one year ago, he flew right over it, observing only from afar the scale of the inundation that had followed Hurricane Katrina. This is an omission he has been paying for, in every sense, ever since.

Katrina, or rather its elemental storm surge and the man-made levees that failed, was the catastrophe that New Orleans had long feared. An emergency plan was supposed to be in place. When it, too, failed as comprehensively as the levees, Mr Bush had an opportunity to show the gifts for leadership he had somewhat tardily displayed after the terrorist attacks of 2001. This time he was unequal to the task.

Public trust in his presidency, as gauged by national poll ratings, has never recovered. The actual damage to Mr Bush and his party may be quantified in the mid-term elections this November. Even now, though, it is clear that Katrina was a crucial moment in George Bush's presidency - perhaps the moment at which its fortunes and reputation were decided.

There are many reasons why Mr Bush's slow response to Katrina has told so negatively on his standing, but in truth they can be reduced to one. His blasé and bumbling response seemed to confirm all the doubts that were voiced about his competence when he first campaigned for election. He claimed then to be able to get things done, to be a good judge of others, and to have the welfare of all Americans at heart.

The suspicion was, however, that he had never graduated from his privileged background, moved in his own ideological circles and had little understanding of life as lived on the wrong side of America's tracks. New Orleans seemed to demonstrate beyond doubt that, when disaster struck, Mr Bush was paralysed into inaction; that his choice of key staff was irresponsible, and that he presided over a federal government that showed callous disregard for a major US city at the very time when federal help should have come into its own.

Reversing this impression will take more than half a dozen presidential visits to New Orleans and the promised $110bn in federal aid - much of it not yet disbursed. That so much of New Orleans is still abandoned, that so few have yet been compensated, and that so many - especially poorer - citizens have felt unable to return, has shown that the "can-do" attitude of coping with adversity has limits, even in a city well accustomed to deprivation.

Of course, Washington's failure to act in a timely and efficient manner was not just a reflection of presidential inadequacy. This was by any standards a major disaster from which few contingency plans would have emerged unscathed. Certain aspects of the US system may also have hampered the response. The strict demarcation of responsibilities between city, state and federal authorities stalls at the first hurdle if the city government has ceased to function. The allocation of key jobs according to political patronage rather than professionalism may have been another factor. And the twin scourges of race and poverty have never been far away, reinforced by a strong strand of US thinking that tends to blame the poor for their misfortune.

Mr Bush cannot be called personally to account for these systemic ills. Where he is responsible is in not exercising the leadership that would have rushed help to New Orleans in its hour of need. This is a failure that will remain alongside the arrogant error of the Iraq war as an indelible stain on his presidency.