Seesm to me, though, that the "howls" were for troops to provide logistical support to evacuate the hell-hole that the Superdome had become, and to get food, water, clothing and medical supplies into downtown. I don't recall that he was calling for them to take over law enforcement, nor was he calling for a declaration of martial law in the area.
In fact, through my swiss-cheesey brain, I seem to recall that it was he that raised the posse comitatus argument, that troops couldn't take over law enforcement activity in "his" city.