Do I have this right - the thrust of your argument is that even after the Federal Government declares a National Disaster, FEMA still cannot respond to the National Disaster until the Govenor 'invites' them. Well, I don't know if that's true or not, but if it as (as you imply), then what does declaring a National Disaster actually accomplish? It looks to me like its just another image thing, like another press conference or photo op.
But like I told the last guy - if your family had suffered at the convention center, you might not be defended the administration so preciously. A coworker of mine had a mother in the hospital. He was on vacation in South Florida and could not get back. They found her in San Antonio, and she is now dying. All they know is that after several days, the hospital was evacuated to the Superdome. They don't know the suffering she endured there - all they know is that her condition changed from recovering to dying. That aren't lauding the Federal response as you are.