Factcheck.org looks into the "Bush cut flood protection funding, people died" argument.

Is Bush to Blame for New Orleans Flooding?

Our fact-checking confirms that Bush indeed cut funding for projects specifically designed to strengthen levees...however..the Army Corps of Engineers – which is under the President's command and has its own reputation to defend – insists that Katrina was just too strong, and that even if the levee project had been completed it was only designed to withstand a category 3 hurricane.

Also, I think that there's a general feeling that FEMA funding has been cut, slashed, gutted, etc. by Bush. I'll just direct you to the latest budget which shows actual numbers for 2004 and 2005 as well as the proposed budget for 2006.