When a tragedy such as that in New Orleans happens, politicians' first thought, although they try to pretend otherwise, is "How can I gain some advantage from this?"
Bush, I think it is fair to say, is eager to use this as 9/11 Part 2 so he can revive his again-failing Presidency. Assuming he doesn't decide to blame the hurricane on Iran, he will try to look solemn (although he hasn't done too well on this one so far), reprise his 9/11-style site visits, play up the looter angle since law and order is as close to national security as he can come on this one, and do whatever he can to rebut the argument that he has over-stretched the National Guard in Iraq. The White House must be thrilled, regarding this opportunity as providential good fortune.
That's how politics is played.
The anti-Bush side, already appearing on various blogs, is that his Administration drastically slashed funding for New Orleans' levies and the like, in the face of warnings that hurricanes were getting worse each year, apparently in response to Iraq war needs, and also that the Administration's downgrading of FEMA impeded a coherent response. But the Democrats won't voice this publicly for some time, not because they wouldn't like to gain from doing so, but because they are scared that Bush will accuse them of politicizing the tragedy while pretending that he isn't doing so himself.
UPDATE: Scott McClellan at his press briefing today, faced with an awkward question about the fact that the White House had cut funding for the specific levies that failed, inevitably took the scoundrel's way out [it's just his job, nothing personal] and decried what he called "playing politics" with the issue. This makes for an interesting fit with the Administration's approach towards 9/11.
There is, of course, no better example of playing politics with tragedies than strategically and selectively saying that people shouldn't play politics with them.
Another amusing note is that Bush said today that no one could have anticipated that the levies would fail. In fact, a government report stated that this was one of the three most likely disasters in the US (along with a terror attack in NYC and presumably earthquake threats in California).