This would probably be considered in poor taste, but what if the DNC were to produce an ad that runs along these lines:
Initial scene: Bush introducing Chertoff, talking about what a great job he's going to do.
Cut to shots of New Orleans
Bush inroducing Brown and saying what a great job he's going to do for FEMA
Cut to shots of starving, desperate victims.
Bush introducing Roberts as his nominee and saying what a great job he'll do.
Tagline: Understandably, we're a little skeptical.