The next three months, political analysts say, could decide whether Mr Bush acquires premature "lame duck" status. It is essential he shows he is in command of the storm relief effort. Otherwise, they warn, his legislative plans, including further tax cuts, a contentious reform of immigration rules, and cuts in the Medicaid healthcare programme, will be in ruins.
As the country went back to work after the Labor Day holiday which traditionally signals the end of summer, the President was everywhere visible at the helm. After chairing a cabinet session, Mr Bush held talks with congressional leaders on the hurricane crisis, before meeting representatives of charities leading the relief effort.
The White House also announced that Vice-President Dick Cheney would travel to the region tomorrow - the latest in a procession of leading officials to inspect the devastation.
Mr Bush tried to distance himself from the blame game already in progress. "I'll lead an investigation of what went right and what went wrong," he insisted.
Even so, the President faces an uphill climb at best. Even before the hurricane struck, his approval ratings had slumped to under 45 per cent, the lowest of his presidency. New polls show that two-thirds of Americans believe the federal government, which he heads, was at fault, both before and after the disaster.
Senator Hillary Clinton, a probable presidential candidate for the Democrats in 2008, has urged the creation of a bipartisan blue-riband commission, similar to the bipartisan 9/11 panel, to examine the handling of the hurricane tragedy.
The petrol price increase in the wake of Katrina, from an average national level of $2.30 to more than $3 (£1.60) a gallon, is also menacing for the White House. Unless swiftly reversed, higher petrol costs will feed into prices across the economy. Most economists expect at least a temporary faltering in growth in the final quarter of the year.
"We must ensure that the national nightmare that was Katrina never happens again," said Joe Lieberman, the senior Democrat on the Senate's Government Affairs Committee which is planning hearings on the disaster. "My feelings went from concern to grief to anger, and then to embarrassment," Mr Lieberman said, expressing a sentiment shared by Republicans as well as Democrats.
The debacle has made a mockery of claims that a new and efficient system had been put in place after the 9/11 attacks to tackle national emergencies - of which a hurricane-provoked flood of New Orleans was near the top of every list.
Indeed, such is the frustration and anger on Capitol Hill that Mr Leiberman's inquiry will be only one of several to be held into the calamity. All are bound to bring fierce criticism of the government.
Barbara: 'Victims poor anyway'
Barbara Bush, the former first lady, courted controversy by pointing out that many of the people forced out of their homes by Hurricane Katrina "were underprivileged anyway". Mrs Bush, who joined her husband, George, on a tour of the Houston Astrodome, said: "And so many of the people in the arena here were underprivileged anyway, so this is working very well for them. What I'm hearing, which is sort of scary, is they all want to stay in Texas. Everyone is so overwhelmed by the hospitality."Reuse content