Alright, let's go.

Who can delcare the state of emergency? Yes the President can.
http://en.wikipedia.org/wiki/State_o..._United_States

How about the fact that Bush's trip to see that area stopped food and supplies from getting in?
http://www.nola.com/weblogs/print.ss...int076556.html

And how about the Homeland Sceurity National Response Plan Set forth in Dec of 2004? It states that, in these "catastrophic" cases, the federal government will operate independently to provide assistance. The NRP also says that, when responding to a catastrophic incident, the federal government should start emergency operations even in the absence of clear assessment of the situation. "A detailed and credible common operating picture may not be achievable for 24 to 48 hours (or longer) after the incident," the NRP's "Catastrophic Annex" states. "As a result, response activities must begin without the benefit of a detailed or complete situation and critical needs assessment."
http://www.dhs.gov/interweb/assetlib...RPbaseplan.pdf