Because Michael Brown was not effective. He did not deliver.
Exactly. FEMA was given what they needed to go in and do a bang-up job but because of the agency's attitude to being managerial Brown simply couldn't move. So the Dems were able to toss their collosal failures onto FEMA's minor failures.
FEMA screwed up simply put. Had FEMA not screwed up then the MSM wouldn't have had a chance in hell of blaming Bush.