Oh, blame Congress. Not that they don't play a role, but that's bureaucratic convenience at its finest.
One of my biggest complaints about Americans is that we live in a representative government, elect people in office (well, sometimes it actually gets counted

), and then blame our elected officials with 100% liability when hindsight shit happens and stuff gets f*cked up. It's just more of that
us vs. them bullcrap mentality, when the truth is -- we
are them. That's the whole frigging point of a representative democracy.
People will bitch and moan about their tax burden and refuse to support certain infrastructure investments through their congressmen, and then when the bridges and levies start collapsing it's all Congress' fault. Not that Congress shouldn't be impaled on spikes and spit at on a regular basis, but it's far too convenient and clean for a voting public to shirk all personal responsibility and roles for any of it. It's a complete cop out. It's a bit of the old saying, "You get the government you deserve." (Far less true in Darfur, of course, but much less of an excuse in the U.S.)
Katrina may have screwed over hundreds of thousands of people who were let down by their local, state, and federal governments. But the truth is they contributed to their own predicament and share some of the responsibility as well -- given who they voted for, measures they supported, where they influenced public policy for tax investments, and their personal level of engagement (or lack thereof) in public policy. (Oh man, am I starting to sounds like Seven by blaming the victims here?

)
Of course, for all my bitching about Americans, at least they're not like most Europeans -- who have only grown a cynical plaque to their psyches, where they've given up on even entertaining the possibility of influencing their fate.