We're all on ideological autopilot
With the exception of the near unanimous calls from both the left and the right for Michael Brown to be fired, the hurricane doesn't seem to have changed anyone's mind at all. Liberals view the disaster through their own ideological lenses and come to predictably liberal conclusions (see Exhibit A). Conservatives reach predictably conservative conclusions about the same disaster (exhibit B).
If Katrina has reminded us of anything, it's that ideologies are immune to worldly events. In fact, ideologies are powerful precisely because they allow us to respond to an almost limitless variety of outside events with just a few basic ideas. They save us from what would otherwise be an overwhelming need to think.
Don't get me wrong; I'm not disparaging ideologies. We'd be paralyzed without them. But don't expect disasters like Katrina, or the war in Iraq, to change anybody's mind.