First, I think we should distinguish attempts at blaming the President for the horrible consequences of the hurricane--as some on other blogs and in the comments are apparently doing--with criticisms of how he is performing NOW in response to events in his capacity as President. I take it that the latter, not the former, was the thrust of Orin's original post. One could completely reject any culpability for these events (via, e.g., theories based on funding for the Corps of Engineers, or National Guard troops diverted to Iraq, etc.) and still be highly critical of the President's current public performance. Whatever one thinks of the former sorts of criticisms, the latter seem perfectly reasonable to offer in a blog--especially from a blogger who might otherwise be more likely to support the current administration. Whatever may or may not be occurring behind the scenes, the President's current public performance is there for all to see and comment on. I cannot say that I have been favorably impressed so far.
Second, government at all levels has obviously not lived up to its promise of being able to anticipate and react to disasters and other social calamities better than nongovernmental institutions. This should not be surprising. Governments are comprised of ordinary human beings with the same limitations of vision and self-interests as those in the private sector (and often, but not always, with far worse incentives)--that is, these human beings confront pervasive problems of knowledge, interest, and power. I have the same reaction every time there are calls for increased government oversight in the aftermath of some failure in the private sector. What gives anyone confidence that government institutions will act with any more prescience? Moreover, it seems often the case that the core functions that are most often used to justify the existence of governments--such as public safety, national defense, and public infrastructure--are often the very tasks that are given short shrift by real world politicians in search of more "elevated," seemingly less pedestrian goals than these. This seems especially the case when the failure to provide these "essential social services" can so often be obscured from public view or, when revealed, responsibility for failure can be shifted to others.
Update: Steve Bainbridge has a nice roundup of other writers who, one way or another, greatly expand on the sentiments of the last paragraph. And it certainly is not "heartless" (in the words of one commentor) to examine the 'root causes' of what seem to be inadequate government responses to this disaster beyond whatever culpability may be attributed personally to George W. Bush.
Update: Lots of good comments in the comment section.