In Mr Bush's position, Tony Blair would have known what to do. A sombre expression, a couple of solemn phrases, then stride towards the nearest TV camera. All Mr Bush needed to say was something along these lines. "Even the mightiest nation can be humbled by nature. But this mighty nation has resources to repair the damage, to bring relief to the stricken. The people of New Orleans will know that they are in our prayers. I also want them to know that, within hours, there will be help."
Mr Bush often uses the phrase "on my watch". If he had spoken along those lines, he would have given the American public the reassurance it sought: that the commander in chief was on the bridge. His approval ratings would now be in the low 60s rather than the low 40s.
So why did the President make such an elementary mistake? Over the past few days in Washington, I have spoken to a lot of Bush supporters, and no one has the answer. Key Whitehouse figures were still on vacation; early reports suggested that Katrina would not be so bad: when Bush staffers think of hurricanes, they think Florida - the most frequent victim - and Governor Jeb Bush, the President's brother. He knows how to cope. No one realised how bad things could get in a less well-run state. All those were contributory factors. Even so, there is no excuse for such a lack of political grip.
But this would have been politics, not life-saving. It is not clear that anything which the President could have done would have saved many lives. The US coastguard service saved thousands of people. It did not need direction from Mr Bush or anyone else. The coastguards knew their business, which is also true of city authorities. But their business is idleness, corruption, crime and waste: a sullen fatalism masquerading as a relaxed approach to life.
Evidence of mismanagement and fraud is mounting. Some levees were useless, not because the floodwater poured over them, but because they crumbled. Why? Although high-qualify concrete had been paid for, low-quality concrete had been used. The savings had been split between politicians and contractors.
For many of its inhabitants, ante-diluvian New Orleans was a ghetto of hopelessness in a land of opportunity. In their case, the flood may bring relief. Transported to other cities, a lot of the refugees have already found jobs: a course of action which would not have occurred to them back home. Like the Highland Clearances, Hurricane Katrina may have forced poor people into a new life and a new mindset. Even if the hurricane joins the clearances in the litany of leftist grievance, the descendants of the victims may benefit.
In the short-term, there is a more urgent question. Can the Republicans recover? Here, the evidence is ambiguous. The President's decisiveness over Rita has repaired some of the damage caused by his reticence on Katrina. Equally, contrasting Louisiana with Texas and Mississippi, where the state authorities shone, is helping middle America to a more balanced view of the blame question. But the Mr Bush's reputation has suffered.
In an embattled world, it is never wise for a politician to seem incapable of rising to the level of events. A lot of Americans are uneasy about Iraq. The casualties, the interminability, the elusiveness of victory: all this depresses even some Republican spirits. In response, the President can only make one point. "This job has to be finished. We will finish it. We will win. Trust me." In recent days, some of that trust has been blown away.
This is not terminal, but the President is dependent on events. Fortunately, Rita proved less ferocious than was feared. Perhaps Mother Nature is not such a partisan Democrat after all. Even so, the Democrats still have Iraq, where the administration needs goodish news by the New Year. If that happened, Republican prospects would improve. It is much easier to campaign on "we toughed it out" than on "we have to tough it out".
Apropos of campaigning, George Bush has run his last race. Two Republican supporters cannot spend three minutes together before coming up with at least four names for the succession. But another big question which no one can answer is: does Condi want to be president?
If she does, George Bush will do everything to help her, and there is an obvious way to start. By next summer, Dick Cheney will have been Vice-President for five and a half years: not bad for a man who has had four heart attacks. Mr Cheney would never lack a medical excuse to retire. If he did so, Mr Bush would nominate his successor and Condoleezza Rice would have first refusal. As an incumbent Vice-President, she would be in a powerful position to become the first black president and the first female president. No one knows what she will decide, but my guess is that the lure of those records will prove irresistible.