In response to jp3flynn...
"They couldn't just walk all over the states' rights willy-nilly, at least they couldn't constitutionally justify it."
Actually, they can in an emergency. Remember, Bush sent in the National Guard to NYC without a specific request of Guliani. And the National Response Plan specifically empowers FEMA to render aid if it feel a disaster is about to occur that affects national security. Besides, once Bush declared a state of emergency in an area, like he did the Sunday before, FEMA is authorized to activate.